We need to Design For Manufacturing systems not just processes


Design for manufacturing (DFM) is, obviously enough, about designing your products with a view to the manufacturing processes that are going to be used. It stands to reason then that it would benefit the design if the design engineer understood those manufacturing processes.

For most engineers who would be considered casual adopters of Design For Manufacturing, this means understanding of factors such as draft angles on moulded parts to aid removal of the part from the mould or jig design to eliminate distortion during the weld process. This is not enough, as this only relates to specific manufacturing processes: casting, welding, etc.

It is equally important to develop an understanding of the overall manufacturing system that is to be adopted. Single, batch or mass production, production cells or moving lines, automated processes, etc. These factors depend on things like customer requirements, demand, takt time and available resources.

Companies are now manufacturing much wider product ranges than ever before. Product life-cycles are getting shorter and there is a growing demand for customisation. Most industry is shifting towards mixed model assembly and flexible manufacturing as a matter of necessity to remain competitive.

The product designer has a massive influence over the success of whatever manufacturing system is adopted and the level of that success in terms of the process efficiency achieved.

An example of a design consideration that carries this influence could be designing commonality across different products parts allowing fixtures and datum locations to be standardised, standard jigs to be used and less inventory infrastructure required. Also modulating products to provide a definite divide between common assemblies and parts or assemblies with variations and customisation. Producing effective standard work documents is another factor which would aid multi-skill working and flexibility for workers.

Manufacture is not just a process, it is not just joining a couple of parts together in different ways. It is a system that includes a demand, sequencing, scheduling, a multitude of various resources, inventory, transportation, constantly shifting priorities, various skills levels etc, etc.

Design for manufacturing therefore is not just designing for a specific process. It is about designing for a production system. It is the responsibility of the design engineers to understand what that entails.

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