Group Technology

Chapter: 5 Group Technology

Group Technology: (GT) is a manufacturing philosophy in which similar parts are identified and grouped together to take advantage of their similarities in manufacturing and design. Similar parts are arranged into part families.

For example: A plant producing 10,000 different part numbers may be able to group the vast majority of these parts into 50 or 60 distinct families.

Chapter: 5

Chapter: 5

Part family:

A Part family is a collection of parts which are similar either because of geometric shape & size or because similar processing steps are required in their manufacture.

Chapter: 5

Parts Classification & Coding.

This method of grouping parts into families involves an examination of the individual design and/or manufacturing attributes of each part. The attributes of the part are uniquely identified by means of a code number.

Parts Classification

Part Design

Attributes

Part Manufacturing

Attributes

Part Design & Manufacturing

Attributes

Basic external Shape Basic internal Shape Length/Dia ratio Material type Part Function Major Dimensions Minor Dimensions Tolerances Surface Finish

Major process Minor Process Major Dimensions Length/diameter ratio Surface finish Machine Tool Operation Sequence Production time Batch Size Annual Production Fixtures Needed Cutting Tools

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Chapter: 5

Coding System Structure

Hierarchical structure

Chain type Structure

Hybrid Structure

Methods of part family classification

• Visual inspection

• Production Flow Analysis(PFA)

• Parts classification and coding system

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Hierarchical Structure: (monocode)

With the Hierarchical Structure, the interpretation of each succeeding symbol depends on the value of the preceding symbols

Chain type Structure: (polycode)

In the chain type structure, the interpretation of each symbol in the sequence is fixed and does not depend on the value of preceding digits.

Chapter: 5

Hybrid Structure:

Hybrid structure is an attempt to achieve the best features of mononcodes & polycodes.

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Chapter: 5 Three parts Classification and Coding Systems

Objective:

The prospective user should first define the objective for the system. It will be used for design retrieval or part family manufacturing or both

Scope and Application:

1.What departments in the company will use the system?

2.What specific requirements do these departments have?

3.What kind of information must be coded?

4.How wide a range of products must be coded?

5.How complex are the parts, shapes, processes, tooling and so forth?

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Chapter: 5

Costs and time:

1.Costs of installation, training and maintenance for their parts classification and coding system.

2.Will there be a consulting fees.

3.How much time will be required to install the system and train the staff to operate and maintain it?

4.How long will it be before the benefits of the system are realized?

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Adaptability to other systems:

1.Can the classification and coding systems be readily adapted to the existing company computer system.

2.Can it be readily be integrated with other existing company procedures (process planning, NC programming and production scheduling)

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Management Problems:

1.Will there be any problems with the union

2.Will cooperation and support for the system be obtained from the various departments involved.

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The benefits of group technology are realized in the following areas.

1.Product Design

2.Tooling and Setup’s

3.Material Handling

4.Production and inventory control

5.Employee satisfaction

6.Process planning procedures.

Benefits of Group Technology