Glenn, Gary M. (1990, ASQC) Glenn Consulting, Virginia Beach, CA
This paper shows how a "sheltered workshop" was able to wield a big quality stick because they learned how to conduct a thorough pre-production inspection of a critical raw material.
To make a wooden picture frame fit together well, the four mitered comers must be consistent in their thickness. Inspection of thirteen pieces of molding stock randomly sampled from a pre-production shipment revealed an unexpected pattern of dimensional variation. Analysis of variance (AOV) was the statistical tool used to probe the sample and detect the pattern of variation introduced by the vendor's production process. Presentation of the data to the vendor's president led to the shipment of 1000 more feet of pre-production molding stock, at no charge to the workshop. Not only was the dimensional stability better on the second pre-production sample, but the workshop found that visual defects (another major cause of picture frame rejections) also went down. Subsequent production runs showed a sustained improvement in both dimensional consistency and visual conformity.
In addition, the workshop persuaded the vendor to increase the average length of the molding stock to reduce the scrap loss from the unusable ends. The vendor had to knock out a wall to do it, but the "handicapped workshop" got its longer pieces. This real world example should encourage readers to try employing more quality tools in their own business situations, no matter how humble. In this way quality knowledge will be increased, resulting in on-going rewards for both the quality practitioner and the organization.
Customer supplier relationships,Inspection,Statistical methods,Case study