DESIGN FOR MANUFACTURE

Design for manufacture (DFM) is a key "enabling" concept for lean manufacture. Easy and fast assembly has an impact right through the manufacturing life of the product, so time spent up front is well spent. A wider view of DFM should consider the cost of components, the cost and ease of assembly, and the support costs.

Cost of Components should be the starting point. Much will depend upon the envisaged production volume: for instance, machined components may be most cost effective for low volumes, pressings (requiring tooling investment) best for middle volumes, and mouldings (requiring even higher initial investment but low unit costs) best for higher volumes. Other issues to do with the cost of components include sourcing and supplier

partnership issues (to what extent is the design done in-house or will it be "black boxed"), the use of group technology (GT - see separate section) perhaps trading off weight against the cost of common parts. Variety as late as possible, and Platforms. Variety as late as possible aims to preserve manufacturing variety options to as late as possible along the manufacturing sequence. This again trades off optimal performance from a design perspective, against reductions in inventories and manufacturing flexibility. Similarly, common "platforms" may be used. Audi and VW Golf share platforms, as do many Japanese calculators often varying considerably in price. The Apple Macintosh uses the platform of a common operating system (MacOS) and common microprocessors (the G3 processor) for a variety of computers.