12813 Ch02 Manufacturing

7/29/2019 12813 Ch02 Manufacturing

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Automation, Production Systems, and Computer-Integrated Manufacturing, Third Edition,by Mikell P. Groover. 1

Part I

OVERVIEW OF MANUFACTURING

Chapters:

2. Manufacturing Operations

3. Manufacturing Models and Metrics


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Ch 2 Manufacturing Operations

Sections:

1. Manufacturing Industries and Products

2. Manufacturing Operations

3. Production Facilities4. Product/Production Relationships

5. Lean Production


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Manufacturing Defined -

Technological Definition

Application of physical and chemical processes to

alter the geometry, properties, and/or appearance of

a given starting material to make parts or products

Manufacturing also includes the joining of multipleparts to make assembled products

Accomplished by a combination of machinery, tools,

power, and manual labor.

Almost always carried out as a sequence ofoperations


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Technological Definition

Fig. 2.1.a


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Economic Definition

Transformation of materials into items of greater value

by means of one or more processing and/or assembly

operations

Manufacturing adds value to the material

Examples:

Converting iron ore to steel adds value

Transforming sand into glass adds value

Refining petroleum into plastic adds value


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Economic Definition

Fig. 2.1.b


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Classification of Industries

1. Primary industries cultivate and exploit natural

resources

Examples: agriculture, mining

2. Secondary industries

convert output of primaryindustries into products

Examples: manufacturing, power generation,

construction

3. Tertiary industries

service sector Examples: banking, education, government, legal

services, retail trade, transportation


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Manufacturing IndustriesInternational Standard Industrial Classification

ISIC Code

Food, beverages, tobacco 31

Textiles, apparel, leather and fur products 32

Wood and wood products, cork 33 Paper, printing, publishing, bookbinding 34

Chemicals, coal, petroleum and their products 35

Ceramics, glass, mineral products 36

Basic metals, e.g., steel, aluminum 37 Fabricated products, e.g., cars, machines, etc. 38

Other products, e.g., jewelry, toys 39


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More Industry Classifications

Process industries, e.g., chemicals, petroleum, basic

metals, foods and beverages, power generation

Continuous production

Batch production

Discrete product (and part) industries, e.g., cars, aircraft,

appliances, machinery, and their component parts

Continuous production

Batch production


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Process Industries and

Discrete Manufacturing Industries


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Manufacturing Operations

There are certain basic activities that must be carried out

in a factory to convert raw materials into finished products

For discrete products:

1. Processing and assembly operations

2. Material handling

3. Inspection and testing

4. Coordination and control

A processing operation transforms a work material from one state ofcompletion to a more advanced state using energy to alter its shape,

properties or appearance to add value to the material.


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Fig. 2.3

Classification of

manufacturing

processes


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Processing Operations

Shaping operations

1. Solidification processes

2. Particulate processing

3. Deformation processes4. Material removal processes

Property-enhancing operations (heat treatments)

Surface processing operations

Cleaning and surface treatments

Coating and thin-film deposition


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Assembly Operations

Joining processes

Welding

Brazing and soldering

Adhesive bonding

Mechanical assembly Threaded fasteners (e.g., bolts and nuts, screws)

Rivets

Interference fits (e.g., press fitting, shrink fits)

Other

An assembly operation joins two or more components to create

a new entity which is called an assembly, subassembly, etc.


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Other Factory Operations

Material handling and storage

Inspection and testing

Coordination and control


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Material Handling

A means of moving and storing materials between processing and/or

assembly operations

Material transport

Vehicles, e.g., forklift trucks, AGVs, monorails

Conveyors Hoists and cranes

Storage systems

Unitizing equipment

Automatic identification and data capture (AIDC)

Bar codes RFID

Other AIDC equipment


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Time Spent in Material Handling

Fig. 2.4


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Inspection and Testing

Inspection examination of the product and its

components to determine whether they conform to

design specifications

Inspection for variables - measuring

Inspection of attributes gaging

Testing observing the product (or part, material,

subassembly) during actual operation or under

conditions that might occur during operation


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Coordination and Control

Regulation of the individual processing and assembly

operations

Process control

Quality control Management of plant level activities

Production planning and control

Quality control


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Production Facilities

A manufacturing company attempts to organize its

facilities in the most efficient way to serve the particular

mission of the plant

Certain types of plants are recognized as the most

appropriate way to organize for a given type ofmanufacturing

The most appropriate type depends on:

Types of products made

Production quantity

Product variety


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Production Quantity

Number of units of a given part or product produced

annually by the plant

Three quantity ranges:

1. Low production 1 to 100 units

2. Medium production 100 to 10,000 units

3. High production 10,000 to millions of units


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Product Variety

Refers to the number of different product or part

designs or types produced in the plant

Inverse relationship between production quantity and

product variety in factory operations Product variety is more complicated than a number

Hard product variety products differ greatly

Few common components in an assembly

Soft product variety small differences betweenproducts

Many common components in an assembly


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Product Variety vs.

Production Quantity

Fig. 2.5


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Low Production Quantity

Job shop makes low quantities of specialized and

customized products

Also includes production of components for these

products Products are typically complex (e.g., specialized

machinery, prototypes, space capsules)

Equipment is general purpose

Plant layouts: Fixed position

Process layout


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Fixed-Position Layout

Fig. 2.6 (a)


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Process Layout

Fig. 2.6 (b)


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Medium Production Quantities

1. Batch product ion A batch of a given product isproduced, and then the facility is changed over to

produce another product

Changeover takes time setup time

Typical layout process layout

Hard product variety

2. Cel lular manufactu r ing A mixture of products is made

without significant changeover time between products

Typical layout cellular layout

Soft product variety


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Cellular Layout

Fig. 2.6 (c)


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High Production (mass production)

1. Quant i ty prod uct ion Equipment is dedicated to themanufacture of one product

Standard machines tooled for high production (e.g.,

stamping presses, molding machines)

Typical layout process layout

2. Flow l ine produc t ion Multiple workstations arranged in

sequence

Product requires multiple processing or assembly

steps

Product layout is most common


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Product Layout

Fig. 2.6 (d)


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Relationships between Plant Layout

and Type of Production Facility

Fig. 2.7


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Product/Production Relationships

Total number of product units = Qf=

Product variety

Hard product variety = differences between

products Soft product variety = differences between models

of products

Product and part complexity

Product complexity np = number of parts in product

Part complexity no = number of operations per part

P

j

jQ1


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Limitations and Capabilities of a

Manufacturing Plant

Manufacturing capability- the technical and physical

limitations of a manufacturing firm and each of its plants

Three dimensions of manufacturing capability:

1. Technological processing capability - the available setof manufacturing processes

2. Physical size and weight of product

3. Production capacity (plant capacity) max production

quantity that can be made in a given time underassumed operating conditions


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Lean Production

Operating the factory with the minimum possible

resources and yet maximizing the amount of work

accomplished

Resources include workers, equipment, time, space,

materials

Also implies completing products in the minimum possible

time and achieving a very high quality level to completely

satisfy the customer

In short, lean production means doing more with less, and

doing it better


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Lean Production and

Manufacturing Activities

Manufacturing activities can be divided into three categories:

1. Value-adding activities - contribute real value to the work

unit

2. Auxiliary activities - support the value-adding activities butdo not contribute value to the product

3. Wasteful activities - do not add value nor do they support

the value adding activities

If not performed, there would be no adverse effect onthe product ELIMINATE !


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Automation Production Systems and Computer-Integrated Manufacturing Third Edition by Mikell P Groover 36

Programs Associated with

Lean Production

Just-in-time delivery of parts

Worker involvement

Continuous improvement

Reduced setup times Stop the process when something is wrong

Error prevention

Total productive maintenance

12813 Ch02 Manufacturing

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