Bylines

Parts consolidation: the critical first step in the device design process
By John Gilligan

Whether the device you are designing is for medical, aerospace, consumer goods or automotive use, it is critical to understand if the parts in that design are absolutely necessary for its function. 

This sounds basic, but more often than not engineers start their design by making the “best” individual components separately without looking at how the device will perform as a complete integrated assembly. One has to step back and interrogate the existence of every single part: it has to prove itself in the system of assembly parts before it should be included.  When you do this exercise, you likely find that 40-50 percent of parts can be combined into single multi-functional components with higher quality, faster assembly times, and greater total cost efficiency.

When this first step is skipped, however, tremendous costs are almost automatically built into the design – and then production – of your device: in warranty and service, inventory, engineering change orders, ERP, supply-chain management and especially in the areas of production throughput and utilization of factory floor space.  A device which has been analyzed correctly, for either manual or automated assembly, will reduce these total “downstream” manufacturing costs.

Most people think about design in CAD-centric ways and conceptualize the whole development process around geometry creation.  But that’s the stage where engineers should be detailing the features of designs that have been pre-optimized in Design for Manufacture and Assembly (DFMA) software—and then preparing their models for prototyping or FEA and eventual output to manufacturing systems. 

So looking at parts for assembly efficiency and “should cost” manufacture is one of the very first critical steps in design: this can happen either at the napkin-sketch stage, or with rudimentary CAD geometries, or with existing products that have components with a long, unquestioned history.