02 gt applications

7/30/2019 02 Gt Applications

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Group TechnologyApplications

Henry C. Co

Technology and Operations Management,

California Polytechnic and State University


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Group Technology Layout


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Group Technology Applications (Henry C. Co) 3

Traditional Layout Types


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Layout the manufacturing facilities

into manufacturing cells.

Each cell is designed to produce afamily of parts that require similar

machinery, tooling, machineoperations, and/or jigs and fixtures.

The routing is greatly simplified byassigning each family of parts to acell.

GT Layout


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GT Layout Benefits

Implied reduction of necessary

control.

Reduced material handling.

Reduced set-up time.

Reduced tooling.

Reduced in-process inventory.

Reduced expediting.

Increase operator expertise.

Improved human relations.


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Limitations

GT layout are not without limits.

Since machines are not sharedbetween cells, more units of machinesare needed for the equivalent capacityin a functional layout.

Also, not all machines can be groupedinto cells. Typically, 30 to 40% of thetotal facility can not be included in anycell and are placed in a remainder cell.

Parts produced in this remainder cellstill have jumbled routings.


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Computer-aided ProcessPlanning


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Process Planning

A process plan establishes the

machining process and parameters tobe used (as well as those machinescapable of performing these

processes) in order to convert a workpiece from its initial form to a pre-determined final form.


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Process Planning

Computer-aided process planning

(CAPP) increases the process planner'sproductivity and improves theaccuracy of the resulting plan.

Accuracy is increased because the new

plan is assembled from pieces ofinformation contained in alreadyexisting plans, which have been testedin actual production. Moreover,

computerization allows the processplanner to quickly evaluate alternativeplans.


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Variant Process Planning

Two approaches to computer-aided

process planning. The variant approach and.

The generative approach.


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Variant Process Planning

The most common approach is variant

process planning, which applies grouptechnology.

Parts requiring similar processes are grouped intofamilies, and a standard plan is created for eachfamily.

The standard plan lists the processes common toall parts belonging to the same family.

When planning for a new part, the standardprocess plan for the family to which the part

belongs is retrieved. Then, using a "same as-except for" technique, the

standard plan is made specific for the part inquestion.


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Classification & Coding


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Generative Process Planning

The generative approach uses decision

rules for the selection of processes,tools, etc.

Based on these decision rules, the

system generates the sequence ofoperations, selects the most suitablemachine tool for the process, andoptimizes the machining parameters.


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Generative Process Planning

Generative process planning is just

beginning to be implemented inpractice.

The development of better 3-Drepresentation of solid objects in CAD,

and advancements in artificialintelligence will greatly encourage itsmore universal adoption, althoughmuch work remains to be done on the

logic of process planning based on 3-Drepresentation.

02 gt applications

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