Process Monitoring in Production Systems with Large Diversity of Products

José Gomes Requeijo, Adriano Mendonça Souza

Abstract

The main objectives of Statistical Process Control (SPC) are monitoring and analyzing the capability of processes. Traditionally, the analysis of the process capability is performed at the end of Phase 1 (preliminary) and periodically during Phase 2 (monitoring) of the SPC, using the indices Cp and Cpk. SPC and capability analysis of production systems with a large diversity of products present difficulties in implementation. In order to meet the needs required by the current production systems, this paper presents methods for both the statistical control and capability analysis of the processes. These methodologies include two situations, when there are sufficient data to estimate the process parameters (mean, variance) and when it does not exist. In the first case, it is suggested the implementation of control charts Z and W and capability indices ZL and ZU. In the second case, when there is a limited amount of data, the authors suggest the implementation of control charts Q and capability indices QL and QU. The methodologies are illustrated with two case studies, concluding that they allow streamline the statistical control of the various processes and reduce the downside, in Phase 2 of the SPC, where the capability analysis is made only periodically.

References

  1. Bothe, D. R., 1988. SPC for Short Productions Runs, International Quality Institute, Northville.
  2. Juran, N. L., 1974. Juran's Quality Control Handbook, McGraw-Hill, New York, 3th Edition.
  3. Kane, V. E., 1986. Process Capability Indices, Journal of Quality Technology, Vol. 18, pp. 41-52.
  4. Montgomery, D. C., 2012. Introduction to Statistical Quality Control, 8th Edition, Wiley, New York.
  5. Quesenberry, C. P., 1991, SPC Q Charts for Start-Up Processes and Short or Long Runs, Journal of Quality Technology, Vol 23, pp. 213-224.
  6. Quesenberry, C. P., 1997. SPC Methods for Quality Improvement, Wiley, New York.
  7. Pereira, Z. L. and Requeijo, J. G., 2012, Qualidade: Planeamento e Controlo Estatístico de Processos (Quality: Statistical Process Control and Planning), 2nd Edition, Foundation FCT/UNL Publisher, Lisboa.
  8. Pyzdek, T., 1993. Process Control for Short and Small Runs, Quality Progress, Vol. 26(4), pp. 51-60.
  9. Shewhart, W. A., 1931. Economic Control of Quality of Manufactured Product, D. Van Nostrand Company, Inc, New York.
  10. Wheeler, D. J., 1991. Short Run SPC, SPC Press, Knoxville, Tennessee, 1991.
Download


Paper Citation


in Harvard Style

Requeijo J. and Souza A. (2013). Process Monitoring in Production Systems with Large Diversity of Products . In Proceedings of the 2nd International Conference on Operations Research and Enterprise Systems - Volume 1: ICORES, ISBN 978-989-8565-40-2, pages 123-129. DOI: 10.5220/0004203501230129


in Bibtex Style

@conference{icores13,
author={José Gomes Requeijo and Adriano Mendonça Souza},
title={Process Monitoring in Production Systems with Large Diversity of Products},
booktitle={Proceedings of the 2nd International Conference on Operations Research and Enterprise Systems - Volume 1: ICORES,},
year={2013},
pages={123-129},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0004203501230129},
isbn={978-989-8565-40-2},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 2nd International Conference on Operations Research and Enterprise Systems - Volume 1: ICORES,
TI - Process Monitoring in Production Systems with Large Diversity of Products
SN - 978-989-8565-40-2
AU - Requeijo J.
AU - Souza A.
PY - 2013
SP - 123
EP - 129
DO - 10.5220/0004203501230129