Parts Churn

At the level of individual parts, there are surprisingly frequent redesigns of automobile components entailing replacement of existing proprietary, non-standard, non-interchangeable designs of automobile parts with new, proprietary, non-standard, non-interchangeable designs which produce no discernible benefit to consumers but which do produce, instead, more expensive vehicles carrying an unnecessarily high cost and potential for severe injury and possible death to drivers and passengers from a part manufacturing or design error stemming from the high rate of parts churn. One also finds exorbitantly high costs arising from the large number of proprietary, non-interchangeable, functionally identical parts which must be produced and stored. “Parts Churn” can be defined as a process wherein a part is designed, tested, has manufacturing tooling produced, then, finally, manufactured and used for 1 to 6 years before being replaced by a functionally identical but non-interchangeable part which is designed, tested, has manufacturing tooling produced, manufactured, and replaces the previous part but offers no advantage to the consumer over the previous part and concomitantly presents an enhanced risk of possible injury and expense to the consumer due to an increased risk of random design or manufacturing error.

Parts Churn is not an engineering function but a process performed for the purposes of marketing or revenue enhancement. It should be stated that real engineers don't do this sort of thing of their own volition. This is what the National Electrical Manufacturers Association says about standards: which are the antithesis of the process described above:

NEMA believes that Standards play a vital part in the design, production, and distribution of products destined for both national and international commerce. Sound technical Standards benefit the user, as well as the manufacturer, by improving safety, bringing about economies in product, eliminating misunderstandings between manufacturer and purchaser, and assisting the purchaser in selecting and obtaining the proper product for his or her particular need.

The lengthy process described above featuring frequent re-design of automobile parts is performed in the production of every vehicle sold in the U. S. and the western hemisphere (except for Tesla). For example, how many horns did Ford Motor Company use during the thirteen years from 2008 through 2020? The question does not refer to the device wherever it may be on the steering wheel or elsewhere which you use to "sound" the horn. Here, the question is about the device that makes the loud, dissonant noise which is almost always located in the engine compartment. Think about this seriously for a minute. Determine the proper number of different horns a manufacturer should make. Then, consider this more difficult question: Why is the number you chose the correct number? Why is that the right choice? Why not more? Unless the answer chosen is one, why not less?