What is DFM?
Design for manufacturing (DFM) is to make a design that is easy to manufacture. The purpose of DFM is to make a better product at a lower cost. Manufacturing engineering is the management of variation which involves 4M (man, machine, material and method).
It is the main part of quality function deployment (QFD). Quality function deployment is a tool for listening to the voice of the customer and answering it.
80% of the manufacturing costs are determined at the design stage itself. Application of DFM at the design phase influences costs. It can reduce the cost of manufacturing very much.
Guidelines for DFM are as below:
- The number of parts should be minimal.
- Use standard child parts.
- Consider variation in process while deciding tolerances.
- Consider current process capability also.
- Design a product so that it is easy to handle.
- Testing the design for manufacturing is a must.
- Involve the production team in the above activity.
Factors to be considered in design for manufacturing:
| Types of Factor | Factor Description |
|---|---|
| Geometry | Part size, Part shape, Tolerance, Roughness |
| Production | Production volume, Production rate, Lead Time & Process |
| Material | Type of material and Material cost |
Geometry Factor:
- Part size
- Part shape
- Tolerance
- Roughness
Production Factor:
- Production Volume
- Production rate (Takt Time)
- Lead Time
- Process
Material Factor:
Which material is used for the availability and cost point of view.
Points to be considered for DFM:
- Market launch time. The objective should be to manufacture right the first time.
- Total number of changes in design till OK part.
- Lead time between design finalization and supply.
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Problem in design for manufacturing:
- Lack of knowledge of design engineer from production shop.
- Lack of physical touch of design and production shop.
- Design engineers see DFM as an activity after design.
- Performance measurements are different for design engineers and production engineers.
Conclusion:
All manufacturing companies with design should consider DFM at the product design stage. Design engineers should have manufacturing engineering experience also. They should discuss with the production team time to time. DFM ensures product change should be minimized. It ensures good manufacturing from starting.