Better Quality
Optimizing the System vs. the Component

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Quality Design  The traditional design approach in the automotive industry is to optimize components (Gormley & MacIsaac, 1989). This component approach is founded on the belief that any design can be broken down into independent and self supporting components. The optimization and the evolution of the whole is assumed from the optimization and evolution of every component (Ziebert, 1991).

From the mid-80s, concurrent engineering methods (ex: DFMA, GT, Taguchi, FMEA, QFD, Value Engineering) and tools (CAD, CAE, CAM, PDM) have been supporting this component approach. Component design started to take into consideration life cycle process requirements. For example, existing components are evaluated according to DFMA rules and the component is modified, preserving its functionality, to improve its ease of manufacturing and assembly. CAD/CAM tools such as feature-based technology allow the simultaneous design process and process planning of components.

Sometimes in designing a new vehicle, our focus on the components, tends to shackle us and blind our very eyes. Then we begin to wonder why we cannot run faster than others and are always playing catchup. Opportunities are all around us. More recently, communications and integration technologies have been helping to close the gaps between the organizations responsible for the various component life cycle processes. 

As the automobile grew in functionality and became a more multidisciplinary product, more component development process took place. Better components were substitute for old ones and new components were simply added to the current design version. Examples of the consequences of this approach applied to automotive electronics show that it has not led to the optimization of the whole product and its lifecyle processes (Ziebart, 1991): 

  1. more control units, sensors and actuators need more space. However, space for components gets less and less because space is required for the convenience of the passengers.
  2. the overall system reliability may decrease because of the increasing number of parts
  3. the increasing complexity of the system structure may deteriorate the serviceability and the handling of the electronics systems
  4. in many cases the driver has been overtaxed by the number of differently reacting electronic systems
  5. solutions for interfaces are often developed in a reactive manner because they must be implemented at that time when the system definition was already finished

Concurrent engineering of components would help component evolution, but only an interdisciplinary, collaborative approach to derive, evolve and verify a lifecyle balanced system can deliver better results that meet customer expectations and public acceptability. Better quality is a result of the fact that the product is developed and verified against requirements that can be traced to original stakeholder's requirements.

References

  • Gromley, J & MacIsaac D.A, 1989 - "The Systems Design Approach (better late than not at all)" - Vehicular Technology, IEEE May Vol 1 pp 401-12
  • Ziebart, W, 1991 - "Car Electronics - Key Factors of Success for the 90s" - Proceedings of the 8th International Conference on Auto Electronics, IEE London pp 1-6