Thursday, 1 June 2006

Automatic Assembly (6/16)

The UMass method of representing the efficiency of a product design is :

Design efficiency, E    = N (H + A) / T

Where :
        E    = automatic assembly design efficiency
        N    = theoretical minimum number of parts
        H    = automatic handling cost per part
        A    = automatic assembly cost per part
        T    = total operation cost

A 100% efficient product design has the following qualities :

- It uses the theoretical minimum number of parts
- The number of insertion operations equals to the theoretical minimum number of parts
- The difficulty level in feeding is similar to feeding a 2.5 cm cube at 1 per second
- The difficulty level of insertion is similar to that of inserting a standard part at 1 per second

Well designed products have UMass design efficiencies between 20% and 30%.  Poorly designed products have efficiencies less than 5%. Alternative product designs can be compared, in terms of design efficiency, to obtain the most economic design.

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