What is DFM?
Design for manufacturing (DFM) is to make a design which is easy to manufacture. Purpose of DFM is to make a better product at 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 design phase influences costs. It can reduce the cost of manufacturing very much.
Guidelines for DFM as below:
- Number of parts should be minimum.
- Use standard child parts.
- Consider variation in process while deciding tolerances.
- Consider current process capability also.
- Design product so that it is easy to handle.
- Testing the design for manufacturing is must.
- Involve production team for above activity.
Factors to be considered in DFM:
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 availability and cost point of view.
Points to be considered for DFM:
- Market launch time. Objective should be to manufacture right first time.
- Total number of changes in design till OK part.
- Lead time between design finalization and supply.
Problem in design for manufacturing:
- Lack of knowledge of design engineer from production shop.
- Lack of physical touch of design and production shop.
- Design engineer see DFM as an activity after design.
- Performance measurement are different for design engineer and production engineer.
Conclusion:
All manufacturing company with design should consider DFM at product design stage. Design engineer should have manufacturing engineering experience also.They should discuss with production team time to time. DFM ensure product change should be minimized. It ensures good manufacturing from starting.