ENG 305 Work Study & Methods Engg Lecture 03

8/9/2019 ENG 305 Work Study & Methods Engg Lecture 03

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Introduction to Work Design

TOOLS


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METHODS STUDY

Systematic recording of existing and

proposed ways of doing work in order to

simplify the job Improve procedures

Improve layout

Reduce human fatigue

Improve use of materials, machines, labor

Improve physical workplace


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Fig. 2.1 Steps in Methods Study

1) Select project

2) Get and present data

3) Analyze data

4) Develop ideal method

5) Present and install method

6) Develop job analysis

7) Establish time standards

8) Follow up


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Fig. 2.1 Steps in Methods Study


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#1 Select Project

Human factors

Technical factors

Economic factors Exploratory tools

Pareto analysis

Gantt chart Fish diagram

Job/Worksite Analysis Guide


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PARETO ANALYSIS (80-20 Rule)

Vilfredo Pareto economist

80% of money held by 20% of people

80% of costs, accidents, injuries,accounted for by 20% of jobs/individuals

Concentrate on those 20%

Plot in descending order as a cumulativeprobability distribution (DesignTools)


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GANTT CHART

Horizontal bar chart of activities

Shade in bar as completed

Any given point in time, a snapshot of thestatus of all activities

Some behind, some ahead of schedule

Again focus efforts where needed Use DesignTools


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JOB/WORKSITE

ANALYSIS GUIDE

Time to go out on the floor

M

eet with supervisor first Explain study (production?)

Select jobs/workers

May need to meet with union also

Never express opinions

Fill out Job/Worksite Analysis Guide


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LABELING OPERATION


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METHODS STUDY (NEXT?)

2) Get and present data

3) Analyze data

4) Develop ideal method

All of these overlap

Use special charts or

procedures

Quicker, more efficient Designed specifically for IEs


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Charts using sequence only

Operation (outline) process chart Flow process chart

Two-hand process chart

Charts using time

Multiple activity chart Simo chart

Charts indicating movement

Flow diagram

Travel chart

Motion analysis


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PROCESS CHARTS

Record sequence of flow for worker,

material, or tools/machines

Outline (operation) vs flow

Supply basic information: date, job, worker

ASME symbols for activities (shorthand)

Vertical lines main flow

Horizontal lines subcomponents to main

Summary compare before and after


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PERT chart

A PERT chart is a project management toolproject management tool used to

Schedule

organize, and

coordinate tasks within a project.

PERT stands forProgram Evaluation ReviewTechnique, amethodology developed by the U.S. Navy in the 1950s tomanage the Polaris submarine missile program.

A similar methodology, the Critical Path Method(CPM) wasdeveloped for project management in the private sector atabout the same time.


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PERT chart


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PERT chart

A PERT chart presents a graphic illustration of a project as anetwork diagram consisting ofnumberednumbered nodesnodes (eithercircles or rectangles) representing events, or milestones in theproject linked by labeled vectors (directional lines)representing tasks in the project.

The direction of the arrows on the lines indicates the

sequence of taskssequence of tasks. In the diagram, for example, the tasks between nodes 1, 2, 4, 8,

and 10 must be completed in sequence.

These are called dependentorserialtasks.

The tasks between nodes 1 and 2, and nodes 1 and 3 are not

dependent on the completion of one to start the other and canbe undertaken simultaneously.

These tasks are called parallelorconcurrenttasks.


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PERT chart

The PERT chart is sometimes preferred overthe Gantt chart, another popular projectmanagement charting method, because it

clearly illustrates task dependencies. On the other hand, the PERT chart can be

much more difficult to interpret, especially oncomplex projects.

Frequently, project managers use bothtechniques.


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How to use it: Identify all tasks or project components.Make sure the team includes people with firsthand

knowledge of the project so that during the brainstorming session all component tasks needed

to complete the project are captured. Document the tasks on small note cards. Identify the first task that must be completed. Place the appropriate card at the extreme left

of the working surface.

Identify any other tasks that can be started simultaneously with task #1. Align these taskseither above or below task #1 on the working surface.

Identify the next task that must be completed. Select a task that must wait to begin until task#1(or a task that starts simultaneously with task #1) is completed. Place the appropriate card tothe right of the card showing the preceding task.

Identify any other tasks that can be started simultaneously with task #2. Align these taskseither above or below task #2 on the working surface.

Continue this process until all component tasks are sequenced.

Identify task durations. Using the knowledge of team members, reach a consensus on themost likely amount of time each task will require for completion. Duration time is usuallyconsidered to be elapsed time for the task, rather than actual number of hours/days spent doingthe work. Document this duration time on the appropriate task cards.

Construct the PERT chart. Number each task, draw connecting arrows, and add task

characteristics such as duration, anticipated start date, and anticipated end date. Determine the critical path. The projects critical path includes those tasks that must bestarted or completed on time to avoid delays to the total project. Critical paths are typicallydisplayed in red..


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PERT EXAMPLE

Fill in earliest possible start time for each event inside the circle

Find the critical path. Mark it with dark lines on the figure, or list the

sequence of arcs.

What is the total project duration (in weeks)?

HW1 due next week

C-1

D-2

F-5

B-3

A-4 E-4

Start

End

$ 100

$ 150

$ 300

$ 600$ 110

$ 500


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Gantt chart

A Gantt chart is a horizontal bar chart developed as aproduction control tool in 1917 by Henry L. Gantt, an

American engineer and social scientist.

Frequently used in project management, a Gantt chartprovides a graphical illustration of a schedule thathelps to plan, coordinate, and track specific tasks in aproject.

Gantt charts may be simple versions created on graphpaper or more complex automated versions createdusing project management applications such asMicrosoft ProjectMicrosoft Project orExcel


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Gantt chart

A Gantt chart is constructed with a

horizontal axis representing the total

time span of the project, broken

down into increments (for example,

days, weeks, or months) and avertical axis representing the tasks

that make up the project (for

example, if the project is outfitting

your computer with new software,

the major tasks involved might be:

conduct research, choose software,install software).


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Gantt chart

Horizontal bars of varying lengths represent the sequences,timing, and time span for each task.

Using the same example, you would put "conduct research" atthe top of the vertical axis and draw a bar on the graph that

represents the amount of time you expect to spend on theresearch, and then enter the other tasks below the first one andrepresentative bars at the points in time when you expect toundertake them.

The bar spans may overlap, as, for example, you may conductresearch and choose software during the same time span.

As the project progresses, secondary bars, arrowheads, ordarkened bars may be added to indicate completed tasks, orthe portions of tasks that have been completed.

A vertical line is used to represent the report date.


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Gantt chart

Gantt charts give a clear illustration of project status, but oneproblem with them is that they don't indicate task dependencies- you cannot tell how one task falling behind schedule affectsother tasks.

The PERT chart, another popular project management chartingmethod, is designed to do this.

Automated Gantt charts store more information about tasks,such as the individuals assigned to specific tasks, and notesabout the procedures.

They also offer the benefit of being easy to change, which ishelpful.

Charts may be adjusted frequently to reflect the actual status ofproject tasks as, almost inevitably, they diverge from theoriginal plan.

Microsoft Project (.mpp)

You must use Gantt chart for your final project!


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MS Projectcan create a PERT chart from a Gantt chart. The PERT (next slide) is another representation of the Proposal project

shown above

The completed tasks have been crossed out while partially completed taskshave one slash through them.

The tasks also show duration, beginning date and ending date.

The critical path (shown in red) is a series of tasks that must be completedon schedule for a project to finish on schedule.

Each task on the critical path is a critical task. Most tasks in a typical projecthave some slack and can therefore be delayed a little without affecting theproject finish date.

Those tasks that cannot be delayed without affecting the project finish dateare the critical tasks.

As you modify tasks to resolve overallocations or other problems in yourschedule, be aware of the critical tasks and that changes to them will affectyour project finish date.


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Critical Path Method (CPM)

Critical Path Method (CPM) charts are similar to PERTcharts and are sometimes known as PERT/CPM.

In a CPM chart, the critical path is indicated.

A critical path consists that set of dependent tasks (eachdependent on the preceding one) which together take

the longest time to completelongest time to complete. Although it is not normally done, a CPM chart can define

multiple, equally critical paths.

Tasks which fall on the critical path should be noted insome way, so that they may be given special attention.

One way is to draw critical path tasks with a double lineinstead of a single line.


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Critical Path Method (CPM)

TasksTasks which fall on the critical path should

receive special attentionspecial attention by both the project

manager and the personnel assigned to them.

The critical path for any given method may shiftas the project progresses; this can happen when

tasks are completed either behind or ahead of

schedule, causing other tasks which may still be

on schedule to fall on the new critical path.

ENG 305 Work Study & Methods Engg Lecture 03

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