AQ:7.1 OVERVIEW

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Most product models use an exact definition of geometry, or other details

It can be useful to have a more abstract representation of a part for some tasks,

- Storage and recall of designs

- Recall of process plans for similar parts

- Classification of designs for analysis of production

GT is used to identify subsets or families of similar parts for the purpose of realizing common features for improved design and process efficiency through standardization.

GT codes can be used to represent products using any combination of geometry, manufacturing processes, and/or function.

The advantages of such a system can be found in,

1. Product design - Group technology allows similar designs to be recalled on the computer. Instead of starting from scratch again.

2. Tooling and setups - standard tooling can be developed for a part family, and then standard setup procedures and times can be used.

3. Materials Handling - Factory floor layout can be updated to reflect part families, and reduce part handling time.

4. Production and Inventory Control - The use of GT to set up standard production techniques allows faster production, therefore less inventory, and Work in Process (WIP).

5. Employee Satisfaction - Grouping of machines allows easier tracking of quality (and achievement).

6. Process Planning - Standard plans can be developed for GT part families. The plans can then be altered to fit, instead of producing a new process plan.

Problems with GT systems are,

1. Not suited to a factory with widely varying products

2. Can have a long setup time, and debugging

3. There are no standard GT codes developed - each GT code application will probably be unique.

4. A GT code may be hard for inexperienced users to read.