Simplification of the economic design of a joint X-bar and R-control chart

Includes bibliographical references (pages [55]-56)This research addresses the problem of simplifying the complex model description and computations in the economic design of a joint X - and R- control chart. A methodology is explored to deal with this problem, after the "basic" model and "simplified" model are formulated to this joint economic design. To prepare for modeling, a combination of cycle-time and system tree figures is used to illustrate the system states and alternative paths in the joint quality control system. These views are helpful in understanding the process with using X and R control charts in statistical control. Computational experiments in simulation are conducted to compare the total expected losscosts between the two models, in order to evaluate whether the "optimal" solutions from the "simplified" model are available to the joint economic design. The experimental results demonstrate that the two models can have very close cost in most cases. This means, the "simplified" model is able to become a new method, which would make joint economic design easier, quicker, and more feasible with computer simulation in statistical process control.M.S. (Master of Science