Cost Modeling of Inspection Strategies in Automotive Quality Control

Investments and decisions in automotive quality control are often based mostly on qualitative arguments. For being able to justify the need for better quality control, quality needs to be given quantifiable monetary value. In this article a cost model is introduced for comparing different inspection strategies and for creating an understanding of the structure of the costs of bad quality in automotive manufacturing. This model is explained and tested using a case example. Information of the costs of quality used in this case example is gathered from four German automotive companies manufacturing welded assemblies. The same case example is used to compare two different inspection strategies: sampling inspection using a coordinate measuring machine (CMM) and 100 % an in-line inspection using a modern optical measuring system, the Mapvision Quality Gate. The selection of the inspection strategy has a significant effect on the cost of bad quality. The model points out that choosing a correct inspection strategy for quality control will lead to a significant increase in the profit margin of the business.

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