The tendency was to over hold coils, causing a slowdown. In some cases the analysis was wrong, and customer complaints ensued. Given that AM/NS Calvert has gauges that detect and report the coating weights at every meter, and that the MES could pass the auto hold system (QDS) customer requirements, the project was created to have QDS perform the evaluations. However, initially using every meter of the strip and comparing each to the customer targets produced too many unnecessary holds.

Our team decided that we should approach the solution by sampling the data less frequently and developing specific zones outside the customer limits and the number of occurrences within those zones. The process was iterative over several months. We would define the frequencies and the zones, and those settings were implemented. From each iteration of the simulations, the team would look at the results and indicate empirically if the offending coils should be held. After several iterations, the sampling and limits were defined and implemented, and the results were realized.

Outstanding results followed; coating weight holds were reduced by at least 50%; we received accurate rework analysis for coils with partial coating weight excursions. As well, graphic visualizations were developed for easily understanding a complicated solution.

 "It was rewarding to work with this group who were both challenging and inspiring," said Blanche Smith, project manager. Others on her project team include Lori Rundy and Dan Weishaar.