On Line Computation of Process Capability Indices

Statistical process control tools and techniques are widely used in assessing and monitoring manufacturing process. Effective implementation of statistical process control tools will improve the productivity and quality; reduce the wastage and improve the business together with various other benefits. Process capability indices are very well used to assess the performance of the production process. However the problem is to keep the produced items in the inventory until to take a decision on the acceptance of the lots based on the outcome of the process capability analysis. An attempt has been made in this paper to overcome such difficulties. As a result we have presented a simple method to assess the process capability indices on line itself, which helps the process as well as the quality engineers to take an instant decision on the manufacturing process whether the process has to be allowed further or to be modified. The method is explained with the help of illustrations.