PETRONAS TECHNICAL STANDARDS

DESIGN AND ENGINEERING PRACTICE

MANUAL

HUMAN FACTORS ENGINEERING - HUMAN/MACHINE INTERFACE AND

CONTROL ROOM DESIGN

PTS 30.00.60.15 MAY 2004

2010 PETROLIAM NASIONAL BERHAD (PETRONAS)

All rights reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the permission of the copyright owner

PREFACE

PETRONAS Technical Standards (PTS) publications reflect the views, at the time of publication,of PETRONAS OPUs/Divisions.

They are based on the experience acquired during the involvement with the design, construction,operation and maintenance of processing units and facilities. Where appropriate they are basedon, or reference is made to, national and international standards and codes of practice.

The objective is to set the recommended standard for good technical practice to be applied byPETRONAS' OPUs in oil and gas production facilities, refineries, gas processing plants, chemicalplants, marketing facilities or any other such facility, and thereby to achieve maximum technicaland economic benefit from standardisation.

The information set forth in these publications is provided to users for their consideration anddecision to implement. This is of particular importance where PTS may not cover everyrequirement or diversity of condition at each locality. The system of PTS is expected to besufficiently flexible to allow individual operating units to adapt the information set forth in PTS totheir own environment and requirements.

When Contractors or Manufacturers/Suppliers use PTS they shall be solely responsible for thequality of work and the attainment of the required design and engineering standards. Inparticular, for those requirements not specifically covered, the Principal will expect them to followthose design and engineering practices which will achieve the same level of integrity as reflectedin the PTS. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from hisown responsibility, consult the Principal or its technical advisor.

The right to use PTS rests with three categories of users :

1) PETRONAS and its affiliates.2) Other parties who are authorised to use PTS subject to appropriate contractual

arrangements.3) Contractors/subcontractors and Manufacturers/Suppliers under a contract with

users referred to under 1) and 2) which requires that tenders for projects,materials supplied or - generally - work performed on behalf of the said userscomply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements withusers, PETRONAS disclaims any liability of whatsoever nature for any damage (including injuryor death) suffered by any company or person whomsoever as a result of or in connection with theuse, application or implementation of any PTS, combination of PTS or any part thereof. Thebenefit of this disclaimer shall inure in all respects to PETRONAS and/or any company affiliatedto PETRONAS that may issue PTS or require the use of PTS.

Without prejudice to any specific terms in respect of confidentiality under relevant contractualarrangements, PTS shall not, without the prior written consent of PETRONAS, be disclosed byusers to any company or person whomsoever and the PTS shall be used exclusively for thepurpose they have been provided to the user. They shall be returned after use, including anycopies which shall only be made by users with the express prior written consent of PETRONAS.The copyright of PTS vests in PETRONAS. Users shall arrange for PTS to be held in safecustody and PETRONAS may at any time require information satisfactory to PETRONAS in orderto ascertain how users implement this requirement.

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TABLE OF CONTENTS

1. INTRODUCTION ........................................................................................................5 1.1 SCOPE........................................................................................................................5 1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS .........5 1.3 DEFINITIONS .............................................................................................................5 1.4 CROSS-REFERENCES .............................................................................................6

2. HUMAN FACTORS ENGINEERING (HFE) ...............................................................7 2.1 GENERAL...................................................................................................................7 2.2 BACKGROUND ..........................................................................................................7 2.3 HFE IN DESIGN .........................................................................................................7 2.4 COSTS/BENEFITS OF HFE.......................................................................................8 3. CONTROL ROOM BUILDING....................................................................................9 3.1 LOCATION..................................................................................................................9 3.2 ACCESSIBILITY .........................................................................................................9 3.3 LAYOUT OF AREAS ................................................................................................10 4. CONTROL ROOM ....................................................................................................13 4.1 LAYOUT....................................................................................................................13 4.2 LAYOUT OF OTHER WORKPLACES .....................................................................13 4.3 WINDOWS................................................................................................................14 5. WORKSTATION LAYOUT .......................................................................................15 5.1 DIMENSIONS AND SHAPE .....................................................................................15 5.2 WORKSTATION CONFIGURATION (CONSOLE)...................................................15 6. ENVIRONMENTAL FACTORS AND FURNISHING................................................16 6.1 AIR CONDITIONING ................................................................................................16 6.2 LIGHT AND OUTSIDE VIEW....................................................................................16 6.3 NOISE.......................................................................................................................16 6.4 MATERIALS AND COLOUR.....................................................................................17 6.5 FURNITURE .............................................................................................................18 7. VDUS AND CONTROLS ..........................................................................................19 7.1 VDU SCREENS ........................................................................................................19 7.2 CONTROLS ..............................................................................................................19 8. PRESENTATION OF INFORMATION .....................................................................23 8.1 INTRODUCTION ......................................................................................................23 8.2 CURSORS ................................................................................................................23 8.3 CODING OF VISUAL INFORMATION .....................................................................24 8.4 ALERTING BY AUDITORY SIGNALS......................................................................24 8.5 DESIGN PROCEDURE FOR VISUAL DISPLAY INFORMATION...........................24 9. ASPECTS OF TRAINING.........................................................................................26 9.1 INTRODUCTION ......................................................................................................26 9.2 VARIOUS TRANSITION GROUPS ..........................................................................26 9.3 METHOD OF DCS IMPLEMENTATION...................................................................27 9.4 TRAINING FOR THE VARIOUS TRANSITION GROUPS .......................................28 9.5 SIMULATION SYSTEMS..........................................................................................31 10 REFERENCES .........................................................................................................33

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APPENDICES

APPENDIX 1 HUMAN/MACHINE INTERFACE (HMI) AND CONTROL ROOM DESIGN CHECKLISTS ..................................................................................................34

APPENDIX 2 EXAMPLES OF 2-D AND 3-D VISUALISATIONS OF A CONTROL ROOM WITH AN INTEGRATED MAINTENANCE WORKSHOP ...................43

APPENDIX 3 EXAMPLES OF STANDARD WORKPLACE CONFIGURATIONS.................47 APPENDIX 4 CONSOLE DESIGN CONCEPTS ...................................................................56 APPENDIX 5 GUIDELINES FOR DEVELOPMENT OF BUILDING LIGHTING PLANS.......59 APPENDIX 6 USE OF COLOUR IN ERGONOMIC DESIGN................................................63 APPENDIX 7 HMI IMPLEMENTATION WITHIN A PROJECT..............................................65

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1. INTRODUCTION

1.1 SCOPE

This new PTS specifies requirements and gives recommendations on the application of Human Factors Engineering principles in the design of control rooms and DCS systems. The aim is twofold: the PTS provides a summary of the state of the art and gives practical recommendations for those involved in new construction projects or plant changes in existing facilities.

1.2 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS

Unless otherwise authorised by PETRONAS, the distribution of this PTS is confined to companies forming part of the PETRONAS, or managed by a Group company, and to Contractors nominated by them.

This PTS is intended for use in oil refineries, chemical plants, gas plants, oil and gas production facilities, and in supply/marketing installations. When PTS are applied, a Management of Change (MOC) process should be implemented. This is of particular importance when existing facilities are to be modified.

If national and/or local regulations exist in which some of the requirements may be more stringent than in this PTS, the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable as regards safety, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this document which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned with the object of obtaining agreement to follow this document as closely as possible.

1.3 DEFINITIONS

1.3.1 General definitions

The Contractor is the party that carries out all or part of the design, engineering, procurement, construction, commissioning or management of a project or operation of a facility. The Principal may undertake all or part of the duties of the Contractor.

The Manufacturer/Supplier is the party that manufactures or supplies equipment and services to perform the duties specified by the Contractor.

The Principal is the party that initiates the project and ultimately pays for its design and construction. The Principal will generally specify the technical requirements. The Principal may also include an agent or consultant, authorised to act for, and on behalf of, the project.

The word shall indicates a requirement.

The word should indicates a recommendation.

Specific definitions and abbreviations

DCS Distributed Control System

diffuse reflection Equal reflection of light (luminous flux) in all directions (also known as Lambert or cosine reflection). No light is lost in this process, i.e. illuminance and luminance values are equal.

E/I/Q Electrical, instrumentation and quality measuring disciplines

FAT Factory Acceptance Test

HFE Human Factors Engineering.

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horizontal illumination

The light falling onto the surface (work station desk or VDU screen) from a horizontal direction.

Illumination The amount of light that falls onto a surface. luminance ratio The brightness of a viewed object with respect to its

surroundings. MOS Maintenance Override Switch

OOS Operational Override Switch

PC Personal Computer

PI Practical Instructor

PLC Programmable Logic Controller

PROSS Process Supervisory System

redundant coding Two or more coding forms in use at the same time

SAT Site Acceptance Test

SMOC

VDU Video Display Unit

vertical illumination The light falling onto a surface (e.g. work station desk or VDU screen) from a vertical direction.

1.4 CROSS-REFERENCES

Where cross-references to other parts of this PTS are made, the referenced section number is shown in brackets. Other documents referenced in this PTS are listed in (10).

.

dmg staff

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2. HUMAN FACTORS ENGINEERING (HFE)

2.1 GENERAL

HFE is the process of integrating human capabilities in the design of products, work places or work systems (plant/facility) resulting in the effective, efficient, safe and healthy functioning of human beings, thereby improving operational and maintenance tasks.

This PTS shall be used as a design tool/checklist in the definition phase to ensure that HFE considerations are laid down in the design package.

Good design means that account is taken of "human factors". In other words, operator tasks are matched to what a human being can and cannot do, and this is taken into account, for example, in the layout and furnishing of control rooms, the presentation of information on VDUs and the design of controls.

HFE should play a role right from the start of the design programme, with user participation being a requirement rather than a luxury. Design reviews should be held during the various design phases in order to avoid the need for subsequent modifications.

If HFE forms an integral element right from the start of a new construction project, an important contribution can be made to safe, efficient and comfortable control of plants, without raising their life-cycle costs.

2.2 BACKGROUND

The use of Distributed Control Systems (DCS) has substantially changed the task of operators in refineries and the chemical industry in recent years. Operator activities now have a more supervisory character, while the greater complexity of plants and process control systems has led to operators being given greater responsibility. Human error can therefore have serious consequences for productivity, safety and the environment.

This PTS is based on research of Human/Machine Interface design in existing control rooms, which has revealed problems that impede the safe, comfortable and effective control of automated systems.

The increasing number of national, European and international statutory directives/guidelines on the Humman/Machine Interface in control rooms has also been taken into account.

The main deficiencies revealed by study of the Human/Machine Interface in control rooms are:

Complaints by users concerning the layout and furnishing of control rooms (console dimensions, noise level in the control room, lighting, inefficient walkways, etc.). Poor presentation of information on VDU; lack of standardization of VDU layout, use of colour and symbols. Problems in how operators process the information of the alarm and annunciation system; in particular the number of alarms and the confusing presentation. Operators are dissatisfied with the training accompanying the implementation of DCS systems.

2.3 HFE IN DESIGN

2.3.1 Points for consideration

Important aspects of HFE in new construction or plant change projects are: The Principal shall ensure that HFE is incorporated in the design process of the project as outlined in PTS 30.00.60.10.. The Principal shall assure that Contractor has HFE competence to carry out HFE scope definition for project (if defining the scope is part of the terms of reference otherwise the Principal shall ensure its own staff are trained).

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HFE should not be considered as an isolated aspect; after all, design decisions all have larger or smaller implications for operational or maintenance personnel. Most design decisions are a compromise. If an optimum HFE solution is not possible, the pros and cons should be weighed carefully, especially if limits are exceeded (e.g. limits for physical or mental load). Re-engineering the task may be required. Making a prototype (mock-up) or a scale model (1:10), even in a simple form, and design reviews are valuable methods for checking and adjusting the design in respect of HFE aspects (accessibility, range, layout, etc.). This is where good human modelling software will be of value. Inclusion of operations and maintenance in the design process is critical for successful HFE design.

2.3.2 User participation

The Principal shall assure user participation during all design phases by including operators in the design/new construction teams in line with PTS 30.00.60.10.

The operator representative should be involved when design requirements for the following aspects are compiled:

Definition of operator philosophy, e.g. distribution of tasks between "outside/inside" operators. Design of control room layout. Design of operator console.

- Dimensions, number of screens, layout of alarm displays. - Communication means. - Location and layout of switch panels. - Keyboard layout. - Room for writing and other tasks.

DCS design, engineering and commissioning. - Alarm philosophy. - Classifying tag numbers into units/groups. - Structure and hierarchy of custom displays. - Detail design of custom/alarm displays. - Training (organization and content). - Interface between FAT/SAT and operators. - Evaluation/changes after start-up.

2.4 COSTS/BENEFITS OF HFE

Taking account of HFE principles in the design will enhance the effectiveness of the design, which in turn will help reduce human error and improve acceptance of the design by operators, thus resulting in a reduction of the life-cycle cost of plants.

The advantages of HFE are: Improved maintainability of control rooms (i.e. designed so that maintenance tasks take less time). Improved operability of equipment. Reduced physical and mental load on employees. Reduced occurences and consequences of human error. Fewer machine failures. Reduction of modifications. Standardization. Enhanced quality of work (well-being). Reduction of prolonged sick leave and permanent disablement.

For further guidance on HFE benefits and their economic quantification see PTS 30.00.60.12.

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3. CONTROL ROOM BUILDING

3.1 LOCATION

The control room location is determined by non-HFE factors such as safety, wind direction, desired free space around the building, potential for expansion, emergency response and the number of plants that are to be controlled from the control room.

Further considerations in the choice of location:

Near the plant Far from the plant

Closer contact with plant Less noise Less odour

Short walking or cycling distances Greater feeling of safety

Civil engineering costs higher Civil engineering costs lower

3.2 ACCESSIBILITY

Accessibility legislation (i.e. governing access by wheelchair users and other disabled persons) shall be reviewed and applied by the Principal in all projects.

3.2.1 General

A relationship model should be developed that identifies critical features and incorporates these data into the final design. Some generic points include:

A single-storey building is recommended. This avoids frequent climbing of stairs and is better logistically. If the building is located within a major hazard area a positive air pressure shall be maintained inside in order to keep dangerous substances out of the building. Access to the building will then be via an airlock with explosion-resistant and gas-proof doors. Automatic doors should be used for this purpose, as these are easier to operate. See PTS 34.17.10.30. and PTS 34.17.00.32. for building requirements. The space between the airlock doors can be used for storing safety equipment (emergency breathing masks, etc.), provided this is allowed for in the design. It is preferable to design the building with a central corridor, along which the various rooms can be reached, e.g. shift supervisors' room, shift room. The routes within the building should therefore be determined beforehand. See Appendix 2 for an example of a Control Room Building. The use of glass walls to separate the various areas should be avoided as far as possible on account of reflections. A (partial) glass wall is acceptable for access control. With respect to building access, account should be taken of equipment as well as all personnel. In practice, this means that it shall be possible to transport equipment easily through the building. If necessary, facilities shall be provided for this.

3.2.2 Emergency exits and escape routes

Escape routes should lead right through the building. Routing them along a wall and far apart is a good practical compromise in the control room. See Appendix 2 for an example of a control room building.

3.2.3 Signposting

Signposting in the control room helps visitors to find persons or locations and indicates escape routes and emergency exits for fire-safety purposes. Signs shall be installed at clearly visible points (pay attention to letter size, colour, etc.). In large control buildings, a floor plan of the building should be provided at a conspicuous place near the main entrance. Various standards specify where signs and emergency lighting shall be installed and the appropriate dimensions, etc.

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3.2.4 Passages/passageways, doors and stairs

In the dimensioning passages, account shall be taken of:

Personnel (with or without personal protective equipment). Equipment. If equipment and furniture are installed, account shall be taken of a free passageway of at least 1200 mm (preferably 1400 mm). Dimensions of doors shall be as follows:

dimensions in millimetres Width Height

Equipment passage

1800 2500

Personnel 900 2100

Dimensions of stairs shall be as follows: - minimum run of tread shall be 200 mm; - handrail shall be located approximately 900 mm vertically above the tread; - adequate anti-slip surface shall be provided on the tread; - spiral staircases should not be installed for safety reasons.

3.2.5 Other personnel and visitors

Other personnel and visitors should enter the control building not via the plant entrance, but via a separate entrance (main entrance) and the central corridor.

A desk should be provided for issuing permits and receiving visitors (see also 3.2.3). The desk shall comply with the legal requirements relating to workplace ergonomics. Special attention shall be give to problems of draft arising from areas with and without positive pressure.

A waiting/shift room for other personnel and visitors should be provided in the control building near the main entrance and the point where people have to report.

Visitors' carpark, number of spaces and location (i.e. adjacency to the control room main entrance) should also be considered in design.

3.3 LAYOUT OF AREAS

3.3.1 Control room

The control room does not need to be situated at the most central point in the building. People not directly involved with the control room should be kept away. The control room should preferably not be situated on a thoroughfare of the plant. The walking distance between the plant and the control room should be kept as short as possible (unless the use of vehicles is envisaged).

3.3.2 General shift supervisor's room

The shift supervisor's room should be located in the immediate vicinity of the control room to facilitate the necessary functional and social contacts.

The shift supervisor's room should not be accessible solely via the control room because the associated comings and goings would disturb the operators' concentration.

A glass wall should not be fitted as partition between the shift supervisor's room and the control room, since the operators would feel themselves under constant surveillance. If visual communication is necessary, a glass strip is an acceptable alternative.

The shift supervisor's room should be clearly signposted (3.2.3).

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The room shall be large enough for office work and meetings. In addition, there should be enough filing space.

If the shift supervisor is absent, there shall be a sign informing visitors where to report.

3.3.3 Computer area DCS location

The computer area should be situated in the direct vicinity of the control room. A raised computer floor should not be installed so that operators have visual contact with every part of the control room. When dimensioning the computer area, account should be taken of the creation of a workplace for engineering tasks. This workplace shall comply with the local legislation provisions relating to workplace ergonomics.

3.3.4 Laboratory

The laboratory in control buildings is often too small. The tasks and activities to be performed should be listed beforehand, whereupon the dimensions and furnishings can be chosen appropriately. The location of the laboratory is a compromise between "maintaining contact" and "isolation". Special attention should be devoted to this point if there is a permanent laboratory worker. Measures should be taken to limit the isolated situation as far as possible; for example by means of a partial glass wall. Video monitoring should be employed for the sake of safety. The laboratory should be situated a short walk from the plant entrance. To facilitate the transport of samples, a short route through the building is necessary. Depending on the nature of the samples, a separate entrance should be provided on the plant side. If toxic substances are used, the laboratory should be isolated for safety and environmental reasons.

3.3.5 Other areas

Area for issuing work permits; this room should be furnished for writing/PC tasks, filing of permits, maintaining plant records and an overview of activities, issue and storage of safety equipment and storage of gas test equipment.

Peak traffic times (i.e. shift handovers) should be considered in the design.

Area for the Practical Instructor (P.I.); sufficient room should be provided, depending on the tasks of the P.I.

Assembly area; it may be desirable in a large control building to provide an assembly area (refuge). This area could be combined with the social area, in which case this should be taken into account when sizing the social room.

Social area; this area should be situated close to the control room, although clearly separated from it. The drawback of distant social areas is that the operators tend to remain in the control room.

Kitchen; this room can be combined with the social room if it is only used for making coffee and the like.

Toilets, washing and changing rooms; these areas should be situated directly off the central corridor. They shall have good mechanical ventilation. The areas should be large enough and reflect the composition of the workforce (male and female). A design with "clean" and "dirty" areas is worth considering, and also the provision of access security (e.g. by means of a key-card).

Office areas; these should be designed for the tasks (writing, VDU work and meetings) to be performed in them. See Appendix 3 for examples of workplace configuraions.

E/I/Q (electrical, instrumentation and quality measuring disciplines) rooms; in practice it is desirable to create separate workplaces for the E, I and Q diciplines in the control building. This area shall be located near or adjacent to the computer area.

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Conference rooms and filing; Conference rooms should be provided in the control room for meetings, training etc. There should also be a separate filing room in the control building.

Storage rooms; sufficient space should be provided in the control building for storing equipment. The room for the breathable air equipment shall be situated near the plant entrance. This shall be large enough to avoid congestion in emergencies.

Smoking area; smoking is forbidden in many control rooms. It is therefore desirable to allocate a room where smoking is allowed. This shall not be combined with the social area.

Lockers and disabled persons facilities.

Bulletin board where essential communications are posted.

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4. CONTROL ROOM

4.1 LAYOUT

4.1.1 Console configuration

Account shall be taken of future expansion when determining the console configuration. The configuration of the plant layout consoles (e.g. mimics) in the control room shall conform with the course of the process, from left to right. This is particularly important for the alarm displays. The consoles should be grouped functionally for each part of the process. Mirror-image layouts shall never be employed in console arrangements for identical processes. The console arrangements for different processes or parts of processes shall be clearly separated. Consoles shall be located so that there are no annoying reflections on the screen (the lighting plan should therefore always be drawn up after the console layout has been determined). Luminance ratios (6.2.2). Arrangement of the consoles next to one another, or at right -angles to one another in a U-shape or in a C-shape is dependent on the number of operators manning the console section and the functional relationship between the various parts of the process. Each of these arrangements has its specific pros and cons. The maximum number of VDUs (video display units) that an operator can physically operate in an upset situation is three next to one another (e.g. 1 overview screen, 1 detail screen and 1 alarm display). This fact, in conjunction with the number of operators needed in the control room, is one of the factors determining the console configuration. Further guidance on control desks is given in EEMUA 201.

4.1.2 Space required for the control room

The space for the control room is determined by:

Space needed for the console configuration (4.1.1). Space for peripherals. Space for the ot her workplaces (4.2). Space for files. Number of operators. Space for meetings. Space for administration (only if building is used during plant shutdowns); for example for charts, spading procedure, etc.).

4.1.3 Space for consoles

The space needed for the console configuration is determined by:

Area of the console configuration. Space needed behind the VDUs for maintenance. Space needed for VDU operation (sitting, standing and walking). Space needed for the partitions. Space for an overview of the whole arrangement. Space for expansion.

4.2 LAYOUT OF OTHER WORKPLACES

It is customary to equip a number of workplaces in the control room for administrative work, checking of drawings ("manual table"), meetings, etc.

The furnishing of these workplaces should take account of their functions.

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Function Requirements for workplace

Reading drawings

Administration (PC)

Meetings

Large enough worktop area

Sufficient seating, large table, desk

Visual partitions are necessary between the various workplaces (sufficient separation, plant boxes, partition wall), but the console shall be visible at all times. When planning the area, it is preferable not to locate any workplace in the direct vicinity of the ventilation grids. In small control rooms (less than 36 m2), measures should be taken to avoid a shut-in feeling (vertical glass strips in the walls, windows, wall decoration, etc.). In large control rooms, measures shall be taken to reduce the noise level and enhance audibility of speech (adjustable volume of auditory signals, "trunking" of communication means and clustering workplaces). In view of the noise and heat they produce, computers and peripherals should be installed in a separate area, as far as possible.

4.3 WINDOWS

The control room should be provided with windows to give a view of the plant and admit daylight. People working in rooms without windows tend to feel "shut in". The windows shall have effective sunshades to achieve the desired luminance ratios and to reduce reflections on VDU screens (vertical, opaque slatted blinds). When the consoles are installed, care shall be taken to avoid annoying reflections on the screens and to ensure that the luminance ratios comply with 6.2.2. Transparent partition walls are also permitted. Daylight openings and outside view openings may be subject to statutory minimum dimensions. Examples could be:

- Area of light openings should be 1/20 of floor area. - Total width of light openings should be 1/10 of the perimeter of the area.

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5. WORKSTATION LAYOUT

5.1 DIMENSIONS AND SHAPE

If a graphics panel with alarms is installed, this panel shall be placed above the VDU. The workstation layout shall have a separate keyboard, which, when pushed back, allows room for writing. For furniture requirements and dimensions, see (6.5). Log books and other necessary documents should also be taken into account.

5.2 WORKSTATION CONFIGURATION (CONSOLE)

The VDU with the most important process information should be positioned straight in front of the operator. Information on screens should be comparable in a horizontal direction. To improve the overview across several screens, workstations should be set up at angles of 10. The configuration should include sufficient writing space for the operator.

Appendix 4 provides detailed pictures of console concepts.

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6. ENVIRONMENTAL FACTORS AND FURNISHING

6.1 AIR CONDITIONING

Control rooms contain a large number of VDUs relatively close together. VDUs generate considerable amounts of heat, and their impact on air-conditioning requirements shall be taken into account at an early stage in the design (ISO 11064-2). For further information regarding air quality and indoor climate, see PTS 31.76.10.10.

6.2 LIGHT AND OUTSIDE VIEW

The lighting plan, based on the control room layout (locations of consoles, workstations, etc.), should be produced at the earliest possible stage of the design. A procedure for developing a lighting plan is provided in Appendix 5. For outside view see (4.3).

6.2.1 Illuminance

The illuminance at the work surface should be between 200 lx and 500 lx. The Illuminance shall be adjustable by means of a dimmer and should be controlled from the console. If colour VDUs are used (information luminance 20 cd/m2), the maximum horizontal Illuminance shall be 320 lx.

6.2.2 Luminance ratios

The luminance ratios bet ween the viewed object, the immediate environment and the periphery shall be in the ratio of approximately 10:3:1.

6.2.3 Light fittings

In order to prevent disturbing reflections on the screens, light fittings shall meet the following requirements: Deep reflector fittings with plastic or metal mirror grids. Screening grids should limit lateral light emission to approximately 40 relative to the horizontal. Outside this range the luminance should not exceed 200 cd/m2. The light fittings shall be positioned relative to the VDUs so that the fittings are outside the operators' field of vision. Equipment of type HF (high frequency, approximately 28 kHz).

6.2.4 Colour temperature and colour reproduction index

The colour temperature should be between 3300 K and 4000 K. For limited daylight entry: 3300 K. For daylight in combination with artificial light: 4000 K. The colour reproduction index (Ra) of fluorescent lamps should be at least 83.

6.3 NOISE

Requirements are laid down in respect of noise and audibility of speech in control rooms. Depending on the nature of the work (degree of concentration) and the necessity for voice communication, there are several different values for maximum noise levels in control building areas (see Table 1).

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Table 1 Maximum noise levels in control room areas

Area Maximum noise level dB(A)

Control room 45 (preferably 40)

Conference room 45 (preferably 40)

Offices 45 (preferably 40)

Plant laboratory 45

Social rooms 50

Changing rooms 50

Computer rooms 60

If there are several control units in a central control room, account should be taken of the following noise sources that could disturb voice communication:

Noise due to the (large) number of VDUs; especially cooling fan noise. Noise generated by acoustic alarms; these should be adjustable for each unit. Noise resulting from communication between plant operator and panel operator; the panel operators of the various units shall not be disturbed by one another. Use of headphones is a possible solution. The sound-absorbent properties of the floor, walls and ceiling can also affect speech audibility in the control room. Extra attention should be devoted to measures for controlling air-borne and contact sound transmission, since a control building is located in the direct vicinity of the plant.

6.4 MATERIALS AND COLOUR

6.4.1 Colour of the room

To achieve a good colour scheme, an interior architect with experience in fitting out control rooms should be consulted.

When choosing the colours in the room (walls, ceiling, furniture, etc.), account should be taken of the luminance ratios (6.2.2). Fairly inconspicuous colours should be chosen, particularly for the large areas (walls, ceiling, etc.). The ceilings should be light-coloured, the walls somewhat tinted, and the floor dark coloured. As regards diffuse reflections of the various surfaces, the following values are recommended:

Table 2 Reflection values for specific Control Room surfaces

Surface Diffuse reflections

Ceiling > 60 %

Walls 40 % to 60 %

Floor 15 % to 30 %

In order not to make an unnecessarily large transition between the screen and the other surfaces of the console these surfaces should have a reflection percentage of between 30 % and 50 %. Light colours should be used for the worktop surface, with a luminance ratio 10:3:1, see 6.2.2).

For colours and their influence on human behaviour, see Appendix 6.

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6.4.2 Materials

When choosing the materials, account shall be taken of their acoustic properties (e.g. density of rubber), light (disturbing reflections) and temperature (cold to the touch). Materials shall in general be antistatic. When selecting floor covering, account shall be taken of: ease of moving office chairs past the consoles, ease of cleaning. There are specific requirements governing the choice of materials for furniture (6.5).

6.5 FURNITURE

6.5.1 General

The furnishing of the control room and office cells in the control building shall be adapted to the users and the office tasks to be performed (VDU, reading and writing tasks). Account shall also be taken of the HFE requirements applicable to the use of furniture.

6.5.2 Desks

Desks shall comply with the following HFE requirements:

Dimensions min. 1200 mm wide (min. 1500 mm if a VDU is used). Height adjustable between 620 and 820 mm above the floor. Provided with integrated cable duct system. Depth of writing/reading work surface: at least 600 mm. Depth of VDU work surface: at least 900 mm. It should be possible to angle the VDU work surface relative to the writing/reading work surface (L-configuration).

6.5.3 Chairs

The chair placed at the console shall comply with the following requirements:

Swivel 360 Seat height adjustable from 410 mm to 530 mm. Flat seat. Backrest depth adjustable from 400 mm to 440 mm. High backrest adjustable in height (at least 370 mm). Short adjustable armrests, adjustable from 200 mm to 270 mm. Tilting mechanism lockable in 3 positions. The chair shall rest on 5 points. Sturdy enough for continuous use.

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7. VDUS AND CONTROLS

7.1 VDU SCREENS

VDU screens include normal CRT (Cathode Ray Tube) type monitors as well as flat panel screens.

7.1.1 Resolution

For displaying graphic symbols, screens should be used which can reproduce at least 1024 pixels x 1024 pixels.

7.1.2 Anti-reflective coating

The reflection factor of VDU screens should be approximately 0.5 % which can be achieved, for example, with a 1/4 lambda coating.

7.1.3 Image refresh frequency

For screens with dark symbols against a light background, an image refresh frequency of at least 70 Hz is needed to avoid irritating flickering. This is especially important if multiple users use multiple VDUs. As the human eye is more sensitive to flicker in the periphery, the refresh rate of the VDUs shall be kept at 70 Hz or above.

7.1.4 Image polarity

Screens with dark symbols against a light background are preferred because they are less susceptible to reflections and have better luminance ratios in the field of view.

7.1.5 Screen luminance

This should be adjustable.

7.1.6 Noise

Noise produced by the VDU shall not exceed 55 dB(A) [preferably 45 dB(A)].

7.2 CONTROLS

7.2.1 Speed of operation and response

Table 3 User activities and maximum response time

User activity Max. response time s

Control activity (e.g. closing valve) 0.1

Simple instruction (e.g. calling up display)

2

Complex instruction (e.g. calling up trend)

5

Error message (directly following end of input

4 (preferably 2)

Request for next page 1 (preferably 0.5)

If the maximum response time cannot be achieved, the operator should be notified of the expected response time, since in practice operators often repeat a control action unnecessarily.

7.2.2 Operating stereotypes

The relationship between an operation of the controls and the resulting movement shall correspond with familiar patterns and habits for local staff. For example, if a process is regulated by turning a knob clockwise, the pointer on the corresponding display shall also

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move clockwise. This is called compatibility. The movement stereotypes for a cursor, joystick, tracker ball, light pen, keyboard, mouse, etc. are shown in Table 4 operators should be included in the design process to confirm the sterotypes.

Table 4 Control function stereotypes

Function Movement

Switch on Up

To right

Forwards

Turn clockwise

Pull a switch

Switch off Down

To left

Backwards

Turn anticlockwise

Press a switch

To right Turn clockwise

To right

Up Up

Forwards

Downs Down

Backwards

Increase Forwards

Up

To right

Turn clockwise

Reduce Backwards

Down

To left

Turn anticlockwise

7.2.3 Compatability

For the display of information, all types of compatability shall be considered, however only two types are emphasised in this PTS. Any control display relationship that is consistent with a prevailing mental stereotype is deemed compatable.

7.2.3.1 Movement Compatability

Movement of the control relates to the movement of the response.

7.2.3.2 Spatial Compatability

Location of the control relates to the position of the response within the display.

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7.2.4 Keyboard

Mechanical keyboards are preferable, partly because of the tactile feedback to the user instead of an auditory signal. This helps to reduce the background sound level.

If auditory feed-back is used, for example by means of a bleep, it shall be possible to adjust the sound level. The keyboard should be connected to the VDU by means of a flexible cable.

The keyboard should not be thicker than 4 cm at its centre.

Membrane keyboards are only suitable for an extremely low typing speed.

The keyboard should be placed at an angle of 5 to 15 from the horizontal.

The layout of the keys should correspond with that of a PC/typewriter.

If much numerical data has to be entered, the keyboard should be fitted with a numerical keypad. The choice then has to be made between a calculator layout and a telephone-type layout.

7.2.5 Cursor

There are two layouts for the cursor control keys:

The inverted T: 3 keys for left, down, and right, in a row, and the up key placed above them in the middle. The "cross" layout: the direction of cursor movement should be indicated on the keys.

The cursor should not disturb the legibility of the screen data.

The cursor should only blink if immediate action is required.

The cursor shall not resemble a symbol already in use.

7.2.6 Tracker ball

A tracker ball (inverted mouse) is a spherical control mechanism which drives two mutually perpendicular sensors. A tracker ball is worth considering if precise and repetitive tasks have to be carried out.

The number of rotations shall not be limited in any direction and the resistance should be equal in every direction of rotation.

The tracker ball is operated by exercising a small tangential force; for faster movements over greater distances, the ball is "flicked" (flywheel effect), after which it is slowed down when the cursor approaches the desired position.

A problem with this mode of operation is, however, that the cursor can run off the screen without being noticed. It is then sometimes difficult to find it again. A knob should therefore be provided to return the cursor to a fixed starting position.

Measures should also be taken to prevent accidental alteration of the position of the tracker ball, for example the use of a switch.

The surface of the tracker ball should be treated to provide good contact with the operator's hand. The ball is not generally intended for gloved use.

The tracker ball should be mounted with its centre of gravity below the working surface. The working surface should be (practically) horizontal.

The diameter of the tracker ball shall, for one-handed operation, be at least 60 mm but not more than 120 mm (preferably not more than 90 mm).

7.2.7 Mouse

A mouse is eminently suitable for point and select tasks. It is unsuitable for data entry.

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7.2.8 Touch screen

Touch screens should be used for selecting subjects, browsing, data entry/retrieval and applications in which it is undesirable or time consuming to divert attention from the screen. This technique can only be used if high precision is not required. Direct feedback (e.g. auditory) should be provided.

The sensitive zones should be large enough for finger touch (at least 4 cm2) and should take account of screen parallax.

A drawback of the use of a touch screen is the static loading of the users arm and the constant recalibration.

7.2.9 Overview of various input media

Table 5 provides an overview of typical characteristics of various inputs devices.

Table 5 Advantages and disadvantages of the standard pointing devices (+ advantage, 0 neutral, - disavantage).

Touch Screen

Light Pen

Graphic Tablet

Mouse Track-ball

Joy-stick

Eye-hand coordination + + 0 0 0 0

Unobstructed view of display - - + + + +

Freedom from parallax problems - - + + + +

Input resolution capability - - + + + +

Flexibility of placement within workplace

- - 0 0 + +

Minimum space requirements + + - - + +

Minimum training requirements + 0 0 0 0 0

Comfort in extend use - - 0 0 + +

Suitability for:

Pointing

Rapid pointing

Pointing with confirmation

Drawing

Tracing

Continuous tracking, slow targets

Continuous tracking, fast targets

Alphanumeric data entry

+

+

-

-

-

0

-

-

+

+

0

-

-

0

-

-

+

0

0

+

+

+

0

-

+

0

+

0

-

+

0

-

+

0

0

-

-

+

0

-

-

-

-

-

-

-

+

-

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8. PRESENTATION OF INFORMATION

8.1 INTRODUCTION

Experience has shown that DCS designers work according to different principles, for example in respect of use of symbols, colours and layout. This can lead to confusion and misinterpretation if several control systems are integrated in a single control room. An excess of auditory and light signals may have an adverse effect on the attention-drawing function of these signals.

A correct layout of displays alone is not sufficient to arrive at an ergonomically acceptable DCS control system. It is just one of the conditions to be met to enable operators to control a DCS system as efficiently as possible. An alarm philosophy matched to the possibilities of the operator (alarm management and alarm presentation) is another important pillar on which the Human/Machine Interface in automated control systems should be based.

Close collaboration between the instrumentation engineer and operator is a prerequisite for arriving at a correct layout of the pictorials. The input of operational know-how by experienced operators and compliance with HFE guidelines in respect of the layout and use of symbols are vital (see Appendix 13).

8.1.1 In principle, do not display equipment which cannot be controlled

In principle, no equipment should be shown which cannot be controlled or for which no action ever needs to be undertaken; information should not be shown that does not contribute to improving the operator's mental picture of the process.

Irrelevant information should be avoided, such as: constantly repeated display of the program name, version number, supplier name. Attention should be paid to the number of digits after the decimal point, and to control loops and manually operated valves, drain and purge connections, etc. which are not fitted with position sensors.

8.1.2 Consistency

Within a display and in similar displays the same or similar information shall appear at the same place and in the same form. The letter or number for menu selection shall be placed to the left of each option, the name of a data field to the left of the relevant data.

8.1.3 Process streams

Intersecting lines should not be used.

Process streams should be shown from left to right and/or from top to bottom. Streams that do not follow this convention (e.g. from right to left, recycles) shall be marked by arrows.

8.1.4 Symbols

Standard process symbols shall be used that are simple as as close as possible to reality.

8.1.5 Touch targets

These shall be the same size as the item to be selected, but in any case at least 2 cm2.

Retrieval times are considerably shorter with a well designed screen than with a poorly designed screen. The number of misreadings is similarly reduced.

8.2 CURSORS

Cursors shall not hinder the reading of other information and should flash only if immediate action is required. Cursors shall be easy and quick to move; this agility shall be controllable by the user (especially useful if the user has limited dexterity capabilities), see (7.2.5).

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8.3 CODING OF VISUAL INFORMATION

The coding methodology shall be consistent (always used in the same way). Redundant coding (two or more coding forms in use at the same time) should be used for information points which are crucial for the interpretation of the process.

Coding should be used when rapid processing is needed.

The following coding methods are available:

Colour: colour coding should only be used redundantly, i.e. in addition to other coding (for meanings of stereotypes, (7.2.2). Brightness: no more than two levels of brightness shall be used; these should still be clearly differentiable at the screen's maximum brightness setting. Reverse video: in order to speed up a retrieval task, a word or code can be inserted in a block with reversed contrast (foreground and background colours reversed). Blinking: only if supplementary coding is used and if direct action is needed: no more than two different flash rates shall be used; the actual word should not blink, only around the word (e.g. exclamation marks or lines); it shall be possible to switch off the blinking (cancellation) (8.8.1). Size of a shape or character: no more than 3 different sizes shall be used.

8.4 ALERTING BY AUDITORY SIGNALS

No more than two different auditory signals should be used.

One continuous signal shall be produced with adjustable volume, at least 15 dB(A) above background noise level (and shall be at least 65 dB(A)).

One intermittent signal shall be produced for high-priority alarms, duration and volume adjustable, at least 15 dB(A) above background noise level (see also ISO 7731).

8.5 DESIGN PROCEDURE FOR VISUAL DISPLAY INFORMATION

It has been found that operators are frequently presentated with confusing information on the screen.

The layouts and coding of pictorials are often inconsistent and insufficiently intelligible, which can give rise to misinterpretation. It is also known that the use of a wide range of symbols, colours and visual signals adversely effects the attraction of attention. This impacts on efficient process control, hinders efficient working and increases the chance of costly mistakes, particularly during upset situations, and entails unnecessarily high mental effort for operators. This situation is called an "interface mismatch".

8.5.1 Interface mismatch

Pictorial designers often proceed from differing assumptions when hierarchically coding data. The mental process model of the designer (e.g. instrumentation engineer) differs greatly from that of the user. Both the grouping of items of information and the displayed detail level and manner of alarm presentation are often based on an idea (of the designer) of the operators task that does not correspond with reality.

A solution for this problem is a systematic integration of the information needs of the operator in the design process (see Table 6), not only regarding normal operating circumstances, but also - and in particular - regarding upset situations. This general design procedure can be employed in existing and new situations. The visual display design procedure addresses the following key questions:

Step 1: How do the operators view the process. Which main and sub-components do they distinguish and what relationships are there between them?

Step 2: Which information from the process is really necessary for a good overview? How accurate must this be and how must it be shown on the screen?

Step 3: How must the results of steps 1 and 2 be intergrated in a prototype?

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Step 4: How do the operators rate the (re)designed graphic in comparison with the old one. How do they perform a number of typical interface activities using the old and new interface designs?

Table 6 Summary table of general design procedure.

DESIGN PROCEDURE FOR VISUAL DISPLAY INFORMATION

Step Purpose Method Result

1 Functional classification (user classification of relationships between the process parts)

Structured discussions between shift teams

Consensus seeking between shift teams

Description of the total process, consisting of a number of main groups, consisting in turn of sub-groups

Optimum browsing sequence between main and sub-groups

2 Process information necessary for overview:

Numeric info

Graphic (non-numeric) info

Desirability scores by operators and process engineer

Questionnaire for operators with regard to colour coding, etc.

Relative necessity of the various sorts of dynamic information and their desired precision, with guidelines

Specifications for graphic representation of structural info (process charts), with guidelines

3 Integration of results from steps 1 and 2

Guidelines form step 2 (e.g. spatial separation of dynamic and structural process Information)

Proposal for VDU graphic, and its configuration on the process control system

4 Evaluation, after a minimum period of experience with the proposal

Questionnaire for operators

Performance tests by operators with the proposed VDU picture (search, comparison and interpretation tasks)

Final version of VDU graphic

Further guidance can also be obtained from PTS 30.00.06.16. which promotes consistency in layout and coding of pictorials, and the effective use of the various coding alternatives.

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9. ASPECTS OF TRAINING

9.1 INTRODUCTION

Good ergonomic design shall be the primary focus for any control room design or upgrade project, and attention to training cannot compensate for poor design. Task requirements and demands shall be fully understood during the design phase, so that design features can be built into the system hardware and software that will support the required levels of task performance and reduce the likelihood of error. The system shall be designed so that the tasks required of end users are within the physical and mental capacities, requirements and expectations of the end users.

Attention to a well designed training strategy and program is vital and should complement good design, but cannot be a substitute for it.

The training strategy and program should be based on thorough Training Needs Analysis (TNA) from which clear training objectives can be established. The training needs will ensure from knowledge of end users, the nature of the design / upgrade project being undertaken, and the required performance outcomes to be achieved. A review of all key functions within the control room should be carried out for the purposes of the TNA, and should not only focus on the DCS. Changes to the control system or strategy may impact other functions and tasks (e.g. engineering functions, Permit to Work functions etc.) and such interactions also need to be identified and understood as part of the TNA.

Projects involving a transition to a DCS will all be slightly different. For example, there are transitions from conventional panel to DCS in large plants and small plants, transition from an old DCS to a new DCS, starting a new plant on DCS, transferring from conventional to DCS by control loop and implementation of DCS during a maintenance shut-down. Every transition to a new DCS therefore requires a tailor-made training strategy and plan. If any aspect of training is to be carried out on-line, safety is of course paramount and the training program should be based on a sound understanding of the hazards and risks and the measures required to ensure these are controlled. Simulators should be used to bring operators skills up to the required levels, especially under upset, infrequently occurring and degraded conditions.

A number of key issues are presented in the following sections.

9.2 VARIOUS TRANSITION GROUPS

It is possible to divide the various transitions into 4 main groups:

DCS implementation in new construction. Transition from conventional panel to DCS, whereby the control elements are transferred on a 1 to 1 basis. Transition from conventional panel to DCS, whereby the plant's control/regulation strategy is changed by using advanced control, quality estimators, etc. Transition from an old DCS to a new DCS.

The training plans to be compiled for the various transition groups have the following characteristics:

a. DCS implementation in new construction

All operators should have acquired a thorough knowledge of the plant by means of training in the construction phase. In general, there is not the pressure of time at start-up. In the precommissioning phase, the operators have plenty of opportunity, with their own DCS and plant, of familiarizing themselves with the operation of DCS and the functioning of the control loops.

In this case, it is sufficient to provide training in the operation of the operator workstation and specific plant-related application training. Operators with considerable experience, preferably with a similar DCS system, should be appointed for this purpose.

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b. Conventional to DCS with 1 to 1 replacement

The operators' plant knowledge is usually sufficient to make the transition. No changes in the control strategy. Transition often under great pressure of time (during shutdowns). No opportunity of training with own DCS and plant.

For this transition, the importance of a good training in operating the system is much greater than for the transition under point A. The operators shall be enabled to gain operating experience by means of a simulator in the period between training for the operation and the actual commissioning of the system.

c. Transition from conventional to DCS with change of control strategy

Plant knowledge regarding the new instrumental control is often insufficient. Transition often under great pressure of time. No opportunity of training with own DCS and plant. Substantial changes in control strategy. This is relatively the most difficult transition and therefore requires the most training.

In addition to the training described in point B, attention shall also be paid to training with the new control systems.

d. Transition from an old DCS to a new DCS

Plant knowledge in the field of instrumental control systems is normally very good. Operators are already familiar with working with a DCS, which simplifies the transition. There is no opportunity of training with the new DCS and the operators own plant. Evaluation of old DCS and making use of this in the new DCS.

This is relatively the most straightforward transition; the operators are used to working with a DCS.

In this case, training in the operation of the operator workstation and plant -related application training are sufficient.

9.3 METHOD OF DCS IMPLEMENTATION

The conventional to DCS transition can take place in two ways:

a. Implementation of DCS during a maintenance shutdown of the plant

The trouble with this is that during a shutdown there is great pressure on the panel operator, since in addition to working with a new control system, he also has to deal with the frequent non-routine situations that occur during the start-up of a plant. Furthermore, start-ups are usually accompanied by a large number of faults/anomalies in the field instrumentation. This can lead to lengthier shutdowns and/or a prolonged start-up period. The tuning of control loops is difficult because during a start-up the loops have not usually attained the normal process conditions. The advantage is that the transition can be made rapidly. This method can be used for transitions of small plants in which a trip or temporary off-spec. production is not critical. It should not be used in large and/or critical plants.

b. Implementation of DCS by loop for loop transfer with the plant in operation

The drawback of this method is that it takes longer before the transition is complete. During the switch-over, double manning of the panel is necessary.

The advantages are:

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By starting with the least critical control loops, the panel men of all shifts can get a better feeling for regulating with the new system. As each loop is transferred, any faults will show up at once. The control loops can be individually tuned as they are transferred.

Critical control loops can be transferred outside day-shift hours, so that the operators have more time to concentrate on the transfer. No low-priority maintenance work is scheduled during the transition.

In the event of a serious process disturbance, for example a leaking meter connection, the transfer can be temporarily stopped. This method should be used in large, critical plants and plants with a complicated start-up procedure.

9.4 TRAINING FOR THE VARIOUS TRANSITION GROUPS

In order to draw up a training plan for the previously mentioned transitions, answers to the following questions are required:

What training needs to be given? Who receives what training? Who gives what training? How can the training be given?

For groups 9.2.a. to 9.2.d., this can be filled in as follows:

9.4.1 DCS implementation in new construction

What training should be given and to whom?

1. Operation of operator workstation.

Such a training course should be tailored to the plant in question.

All operators.

2. Plant-specific application training.

The aim of this training is to familiarize operators with the applications in all peripheral systems, such as PROSS and safeguarding PLCs in association with the operator workstation.

All operators.

3. Special training for the operators and Plant Instructor.

The activities for staff involved in the project include creating pictorials, writing (improving, keeping up to date) operating manuals, and training the operators.

4. Training in control loops and safeguarding systems.

In general, this is included in the plant's overall training package. All operators.

Who gives what training?

Since the DCS supplier is the only party with a complete knowledge of the hardware, software and configuration used, that supplier alone is able to provide the operator workstation training and the project-related training at the desired level. The training on peripheral systems and the plant-specific application can also be given by the contractor, but alternatively this may be provided by a simulator trainer from the internal training centre with possible support from craft departments involved in the new construction project. Control loops and safeguarding training can be given by the Instrument department and Plant Instructor (PI).

How can the training be given?

As the operators do not yet work on a full-shift basis, the training can be given at any convenient moment during day-shift hours. The training can be given on the plants DCS.

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9.4.2 Conventional to DCS with 1 to 1 switchover of control loops

What training should be given and to whom?

1. Operation of operator workstation.

Such a training course should be tailored to the plant in question.

All operators.

2. Gaining experience with the operator workstation.

By making use of a workstation with a simulation program, it is possible in the period between the course on the operation of the operator station and the implementation of the DCS to gain experience with the operation and control of a plant running under DCS.

All operators.

3. Special training for the operators and Plant Instructor.

The activities for operators involved in the project include creating pictorials and writing operating manuals.

Who gives what training?

The training wherey experience is increased with the aid of a simulator can be provided by the local training department, if this department has an operator workstation. The other training is given by the same persons or bodies as for transition group a.

How can the training be given?

The course on the operation of the operator workstation has to be given on the supplier's premises. This means that small groups will have to be formed of representatives from all shifts.

9.4.3 Transition from conventional to DCS with changes in control strategy

What training should be given and to whom?

1. Operation of operator workstation.

2. Gaining experience with the operator workstation.

By making use of a workstation with a simulation program, it is possible in the period between the course on the operation of the operator station and the implementation of the DCS to gain experience with the operation and control of a plant running under DCS.

All operators.

3. Special training for the operators and Plant Instructor.

4. Training in control loops, safeguarding, sequence programs, etc.

5. Application training.

All changes in the control strategy shall be passed on to the operators with the aid of the control narratives and operating manuals. All operators.

Who gives what training?

The training whereby experience is increased with the aid of a simulator can be provided by the training department, if this department has an operator workstation.

The other training is given by the same persons or bodies as for transition group a.

The application training can be given by the Plant Instructor. The course on control loops etc. can be given by the instrument engineer and Plant Instructor.

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How can the training be given?

The course on the operation of the operator station has to be given by the supplier. This means that small groups will have to be formed of representatives from all shifts.

9.4.4 Transition from old DCS to new DCS

What training should be given and to whom?

Operation of operator workstation Such a training course should be tailored to the plant in question.

All operators.

2. Plant-specific application training

The aim of this training is to familiarize operators with the workings of all applications in the peripheral systems, such as PROSS, and safeguarding PLCs in association with the new operator workstation. All operators.

3. Special training for the operators and Plant Instructor.

The activities for staff involved in the project include creating pictorials, writing operating manuals and training the operators.

Who gives what training?

Since the DCS supplier is the only party with a complete knowledge of the hardware, software and the configuration used, that supplier alone is able to provide the operator workstation training and the project-related training at the desired level. The training on peripheral systems and the plant-specific application can be given by the Plant Instructor with possible support from craft departments involved in the project.

How can the training be given?

The course on the operation of the operator workstation can be given by the supplier to the shifts.This should preferably take place in small groups formed of representatives from all shifts. Since the operators already have experience of working with DCS, it is also possible to opt to train a number of people who will in turn train the rest of the operators. This will, however, require a workstation to be available for training purposes.

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9.4.5 Overview of training

Table 7 Training Register

Subject of training

Who is trained?

Who gives training?

A B C D

Process-related knowledge of plant

All operators PI X

Control-related knowledge of plant

All operators Instruments or Process Control department

X X

Familiarity with DCS

All operators DC S Supplier, Contractor

X X X

Use of operator station controls

All operators DCS Supplier, Contractor

X X X X

Control peripherals

All operators Contractor, PI

X X X

Writing manuals, making pictorials

PI (Plantin-structor)

DCS supplier X X X X

Simulation All operators Training Department

X X X X

A. DCS implementation in new construction.

B Conventional to DCS with 1 to 1 switch over.

C. Conventional to DCS with change of control strategy.

D. Transfer of old to new DCS.

9.5 SIMULATION SYSTEMS

A simulator shall be an integral part of the DCS supply.

9.5.1 Introduction

A simulation system makes use of a mathematical model in a computer and can reproduce the behaviour of all the variables in a plant or unit.

Simulation systems are used for operator training in many plants, but not much information is available regarding the advantages or costs/benefits of simulators. However, some research has been done and the conclusion is that intensive and specific training of the operator is vital for a good understanding of the new process facility. Good follow-up practice with the aid of simulation of the operator's own process is very important and results in savings, provided it is carefully planned.

In the following sections a number of applications and advantages of simulators are summerized, based on literature and experience inside and outside Shell.

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9.5.2 Application of simulator in relation to life cycle phases of a plant

Based on the various life cycle phases of a plant, a number of activities can be distinguished for which a simulator could be useful.

Pre-start -up engineering tests: check of equipment and dynamics of the process, control strategies and plant procedures.

Start-up training: training of start-up teams with regard to the course of the process, equipment, controls, start-up procedure, etc.

Training for operation:

a. Basic training for operators in respect of instruments, individual controls, process and control systems. b. Familiarization of engineers, managers, etc. with the process. c. Training of operators in process optimization. d. Training of operators in dealing with upset situations. e. Training of engineers in respect of plant modifications, process changes and new control systems. f. Refresher training for operators.

9.5.3 Advantages of simulator

The following positive effects can be distinguished, relating to the activities 1, 2 and 3 listed in 9.5.2:

1. Pre-start-up engineering tests

Savings due to the fact that necessary plant and/or control strategy modifications can be carried out more quickly and thus at lower cost: "build only once". Savings in plant operating costs because design modifications can be carried out before the start-up. 2. Start-up training

Savings in costs of start-up training Shorter start-up training Savings from a quicker start-up thanks to more effective training.

3. Operation training

Savings in time and costs of basic operator training. Savings due to managers, engineers, etc. being more familiar with the plant dynamics and the potential upsets of the plant. Savings due to training of operators in fine tuning of controls to optimize the process (only in the case of a "high-fidelity" model). Savings by operators being better trained and having more confidence in the control system. Savings from raised production as a result of a more efficient operation of the plant.

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10 REFERENCES

In this PTS reference is made to the following publications: NOTES: 1. Unless specifically designated by date, the latest issue of each publication shall be used (together

with any amendments/supplements/revisions thereof).

PETRONAS STANDARDS

Human factors engineering in projects PTS 30.00.60.10.

Human factors engineering Investment justification model

PTS 30.00.60.12.

Human factors engineering Hierarchy attention coding for graphical display design (under development)

PTS 30.00.60.16.

Heating, ventilation and air conditioning for plant buildings

PTS 31.76.10.10.

Design and engineering of buildings PTS 34.17.00.32. Blast resilient and blast resistant control Buildings/field auxiliary rooms

PTS 34.17.10.30.

BRITISH STANDARDS

Process plant control desks utilising human-computer interfaces A guide to design, operational and human interface issues

EEMUA 201

Issued by:

Engineering Equipment and Materials Users Association 45 Beech Street London United Kingdom EC2Y 8AD

INTERNATIONAL STANDARDS

Ergonomics danger signals for public and work areas Auditory danger signals.

ISO 7731

Lighting of indoor work places ISO 8995

Ergonomic design of control centres Part 2: Principles for the arrangement of control suites.

ISO 11064-2

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APPENDIX 1 HUMAN/MACHINE INTERFACE (HMI) AND CONTROL ROOM DESIGN CHECKLISTS

These checklists identify any bottlenecks in existing control rooms, panel rooms and other relevant human machine interfaces, and include a checklist for project management purposes. The relevant checklist can also be used to determine the scope of a new building and/or HCI project.

0. CONTROL ROOM

n.a. yes no specification

SPATIAL CONFIGURATION

1 Are the consoles configured in accordance with the logical process sequence?

2 Are the alarm displays configured in accordance with the logical process sequence?

3 Are the consoles functionally grouped per production process?

4 Is there a clear and visible separation between the console configurations of the various parts of processes?

5 Have mirror-image configurations been avoided for identical processes?

6 Have efforts been taken to minimize reflections in the console configuration?

7 In the console layout (one on top of the other, C-form, U-form, circle), has account been taken of the number of operators controlling the process? Has account been taken of "normal" operating conditions?

8 Has it been made possible for operators to retain an overview of the control room even with minimum manning (e.g.: visibility of panels, acoustic alarms, etc.)?

9 Has the need been avoided for operators to constantly walk back and forth in the control room, with minimum manning?

10 In the console configuration, has account been taken of the fact that during an upset an operator can cope with 3 monitors at maximum (e.g., an overview monitor, detail monitor and alarm display)?

SPACE REQUIREMENT

11 Is there sufficient space in the control room for:

- required overview of the entire configuration - console maintenance (N.B.: including access behind

the monitors)

- sitting, standing, walking - making separations - number of operators - peripherals - administration - discussion - document storage - special circumstances such as plant shutdowns

(space for drawings, procedures, etc.).

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n.a. yes no specification

CONFIGURATION OF OTHER WORKPLACES

12 Is the configuration of the other workplaces functional?

13 Has account been taken of the tasks to be performed, e.g. working surface of sufficient size for reading drawings, and sufficient chair space for discussions?

14 Is it critically important for the console to be visible from these workplaces and has account been taken of this (note: height of plant pots, dividing walls, etc.)?

15 Has the fitting of ventilation grilles directly above workplaces been avoided?

16 Have measures been taken so that operators do not feel hemmed in, particularly in small control rooms (< 36 m2), e.g. by means of: vertical glazing panels in walls; windows; wall decorations, etc.?

17 In the control room layout, has sufficient attention been paid to ensuring that normal speech is intelligible?

18 Has the housing of "unnecessary" equipment in the control room been avoided (because of the heat and noise generated, such equipment should be housed in separate rooms as far as possible)?

DAYLIGHT/WINDOWS

19 As regards the ingress of daylight and windows, has sufficient account been taken of specified minima (e.g. area of light-admitting openings to be 1/20 of floorspace, total width of light-admitting openings to be 1/10 of room perimeter)?

20 Are the windows sufficiently blinded against sunlight glare (e.g. by using vertical light-obscuring slats)?

21 Has sufficient account been taken of the required luminance ratio (10:3:1)?

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2. CONSOLE LAYOUT

n.a. yes no specification

DIMENSIONS AND FORM 1 Do the console dimensions comply with anthropometric

data, for seated and standing personnel?

- height of monitor - angle of monitor to horizontal - height of working surface - depth of working surface - leg room underneath console - thickness of working surface - use of double monitors (one on top of the other) - footrests and their angle to horizontal 2 Is there sufficient room for:

- writing by operators - communication facilities - support of lower arms and wrists, etc. 3 Are the graphic panels with alarms placed up in the tertiary

face zone?

4 Is there sufficient writing space for operators alongside a fixed keyboard?

5 Have measures been taken to ensure that loose keyboards cannot drop off the console (note: cord length)?

CONFIGURATION 6 Can operators sit straight in front of the most important

monitors?

7 Are monitors set at the right working height and the right angle for operators, including any standalone PCs?

8 Is information displayed on monitors compared in the horizontal direction?

9 Has it been made possible for the operator to survey several monitors from one position

NOTE: Console in a curved bay of at least 10?

10 In the layout of important monitors, has sufficient space been allowed for several operators to work at the console (upsets, calamities, etc.)?

11 In the selected number and positioning of communication facilities, has the need been avoided for operators to constantly move around?

12 Is there sufficient room for instrumentation staff to work?

13 Is accessibility for maintenance adequate?

14 Can components be readily fitted and dismantled?

15 Can cables be readily routed through the console?

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3. PHYSICAL FACTORS

n.a. yes no specification

LIGHT 1 Is the lighting plan attuned to the configuration of the

various workplaces (to avoid reflections)?

2 Are there blinds (which shall limit sidelong light emission to 40 degrees relative to horizontal) to prevent reflections?

3 Does the illumination at the operator's working surface measure 200 lx to 500 lx?

4 Is the illumination variable (dimmer)?

5 Is the illumination variable from the console?

6 If colour monitors are used, has a maximum permissible horizontal illumination of 320 lx been allowed for?

7 Do the luminance ratios between the visual task, immediate surroundings and periphery comply with the ratio 10:3:1?

8 As regards the placement of the light fittings, has it been ensured that they do not fall in the operator's field of vision, in relation to the monitors?

9 Does the colour temperature lie between 3300 K and 4000 K?

NOTE: 3300 K with limited ingress of daylight or 4000 K with daylight plus artificial light.

10 Is the colour reproduction index (Ra) of the fluorescent lamps approximately 83?

CLIMATE

11 Does the climate control take account of the heat generated by the number of operators and equipment?

12 Is the air refresh rate by mechanical ventilation approximately 50 m3 per hour per operator?

13 As regards the intake of outdoor air, has account been taken of abnormal circumstances (which could adversely affect quality - risk of noxious and other odours)?

14 Have measures been taken to counteract the spread of dust and/or fibres?

15 Is the installation sufficiently maintenance-friendly (inspection and cleaning facilitated)?

16 Is equipment which may result in "dry air" kept outside the control room (e.g.: printers, photocopiers, etc.)?

17 Does the indoor climate during the heating season satisfy the following criteria:

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n.a. yes no specification

- average convection and radiation temperature between 21 C and 23 C?

- air temperature difference between 1.1 m and 0.1 m above floor level less than 3 C?

- average air speed lower than 0.15 m/s? 18 Does the indoor climate outside the heating season satisfy

the following criteria:

- average convection and radiation temperature between 23 C and 26 C?

- air temperature difference between 1.1 m and 0.1 m above floor level less than 3 C?

- average air speed lower than 0.25 m/s? 19 Is there sufficient and effective sun blinding?

20 Is the heating controllable by the operator?

NOISE 21 Have sufficient measures been taken to eliminate unwanted

noise so as to improve the intelligibility of speech? For example: fan noise, acoustic alarms, communication, noise from adjoining rooms, noise of opening doors, silencer hoods for printers, etc.

22 Are the acoustic alarms adjustable?

23 Are there silence settings on the alarms?

24 Is the monitor feedback signal adjustable?

25 Is the sound level below 45 dB(A) in the control room?

26 Is the monitor sound level below 55 dB(A)?

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4. USE OF MATERIALS AND COLOURS; FURNITURE

n.a. yes no specification MATERIALS 1 In the choice of materials, has account been taken of the

implications for noise, light and temperature?

2 Are the materials antistatic?

3 In the choice of floor coverings, has attention been paid to: readily cleanable, shifting of office chairs along console, soiling tendency, luminance ratios, etc.?

4 Do the chairs have sufficiently rugged upholstery?

5 Have "warm" materials been used in contact areas between parts of the body and furniture and/or console?

COLOUR SCHEME (see also Appendix 6) 6 In the room's colour scheme (walls, ceiling, furniture), has

account been taken of the correct luminance ratio?

7 Have excessively "striking" colours been avoided, particularly for the lar