Measurement and use of process capability in statistical process control activities in a printed circuit board manufacturing domain

Process capability is the ability of a single process to produce the desired output. Process capability indices are used to quantify process capability. Although process capability indices are widely used in industry in Statistical Process Control (SPC) applications, there are criticisms among researchers on process capability studies. The following arguments are common: there is a lack of guidelines for SPC and process capability implementation, there is no widely accepted and appropriate sample size for performing process capability studies, and there is a void concerning the use of process capability studies in quality improvement and multivariate process capability indices. This research brings new insights and analytical solutions to these problems.; In this research, the necessary conditions for performing process capability studies are discussed, a set of guidelines for implementing SPC is suggested that is based on that discussion and the place of process capability studies in an overall SPC implementation is suggested. The implementation of the suggested guidelines in a local Printed Circuit Board (PCB) manufacturing company enables the improvement of guidelines, as well as, acts as a good case study to highlight the benefits gained and problems encountered during SPC implementation.; A series of analytical tools, such as simulation and trend analyses, are utilized to find an appropriate sample size for performing process capability studies. A case study based on the suggested sample size is then utilized for verification purposes, followed by a comparison of the existing research and the suggested sample size.; This research also focuses on the use of process capability indices for quality improvement activities, and examples are provided on the utilization of process capability indices as a decision-making and long-term process-monitoring tool.; Finally, a system process capability index that provides a quick summary, via a single expression, of a multi-staged manufacturing system is proposed. The limitations, assumptions and the characteristics of the proposed index are discussed. Then, case studies are provided in the calculation and the use of the proposed system-based index.