Design for Manufacturing (DFM) is an integrated process with New Product Development and its main objective is to design a product that is easy and economical to manufacture.
The fact that around 70% of manufacturing cost is assigned to materials, processes and assembly, it is a very important step in the design phase that has a large impact on the overall cost of the product at launch.
Design for manufacturing guidelines
The DFM principle follows a number of guidelines that are valid across many product categories. It helps the design team to reduce cost and design a product that is as easy to manufacture as possible. The guidelines are based upon the following:
- Reduce the total number of parts – this is probably the best opportunity for the designer to reduce cost. The fewer parts there are, the less the cost of inventory, handling, storage, processing time, assembly time, inspection time etc.
- Reduce the number of fasteners – The fewer fasteners mean there is less operator interaction and movements, therefore saving on assembly time. It also reduces the individual inventory count on the BoM.
- Use common parts across different product lines – standard items such as gears, bearings, electrical and electronic components that are already being used on other products should be considered for the new design.
- Design using Poka Yoke principles – error proofing eliminates assembly errors ensuring the product is assembled correctly the first time. This makes assembly easy and more time efficient.
- Design in self-locating features – if parts can self-align or self-center during assembly, this eliminates assembly issues and potential failures later.
- Standardize parts – using standard off the shelf common parts reduces order lead time and parts are of a known quality level.
- Design parts so they can be consistently produced – parts should have tolerances that are within process capability and can be produced in mass with minimal errors.
- Minimize part reorientation or operator awkwardness – as the product is being assembled on the production line, it is always best if the part is not turned and spun or flipped at every workstation, this increases assembly time and complexity.
- Eliminate the need for adjustments – making adjustments to a product in order for it to be correct is both time-consuming as well as having the opportunity of setting errors which could result in failures later.
If these design for manufacturing guidelines are followed, there is every chance that the new product will be assembled quickly, easily and at the optimal cost.
See how DFM fits into NPI in more detail in The New Product Introduction Process Guide for Hardware Startups.