Dillow, Russell C.; Brown, Bradford S. (1997, ASQ) Chevron Chemical Company, Orange, TX; Houston, TX
Laboratory test results have reduced variability among three laboratories under the management of a cross-functional quality specialist team. The team consists of two individuals from each of the laboratories. Their cross-check procedures each month cover 89 measurement processes. Cross-check activities include using a common reference material among the three laboratories for each test property. Every month, each laboratory reports average and variability statistics on routine analysis of the reference materials. If significant differences occur from laboratory to laboratory, the team recommends corrective action. This improves standardization and communication among the laboratories while using control chart data already on hand at each location. These analyses cover routine activities. They are not merely snapshots, nor do they require special testing. The cross checks apply to situations in which identical instruments and methods are used at each laboratory, as well as to situations in which the laboratories use multiple instruments and different test methods for the same property.
Chemical and process industries,Testing,Measurement and control,Control charts