Abstract
The sequential probability ratio test (SPRT) chart is a desirable tool for monitoring manufacturing processes due to its high effectiveness. It is especially suitable for applications where testing is very expensive or destructive, such as the automobile airbags test and unaxial tensile test. This article proposes a design algorithm for the SPRT chart in which the reference value (γ) of the SPRT chart is optimized. The design algorithm increases the overall effectiveness of the SPRT chart by more than 10% on average. Moreover, the improvement in detection effectiveness is achieved without any additional difficulty in implementation. A design table is also provided to facilitate quality engineers to design the SPRT chart.
Similar content being viewed by others
References
Wu Z, Xie M, Liu QC, Zhang Y (2006) SXC control chart. Int J Adv Manuf Technol 30:444–451
Sheu SH, Tau SH (2006) Generally weighted moving average control chart for monitoring process variability. Int J Adv Manuf Technol 30:452–458
Jiao JX, Helo PT (2008) Optimization design of a CUSUM control chart based on Taguchi’s loss function. Int J Adv Manuf Technol 35:1234–1243
Arnold JC, Reynolds MR Jr (2001) CUSUM control charts with variable sample sizes and sampling intervals. J Qual Technol 33:66–81
Zhang S, Wu Z (2007) A CUSUM scheme with variable sample sizes for monitoring process shifts. Int J Adv Manuf Technol 33:977–987
Stoumbos ZG, Reynolds MR Jr (1997) Control charts applying a sequential test at fixed sampling intervals. J Qual Technol 29:21–40
Wald A (1947) Sequential analysis. Wiley, New York
Lynn J (1996) Calculating the exact characteristics of truncated sequential probability ratio tests using mathematica. Proceedings of 12th Symposium on Comput Stat 26–30
Lee GP, Stefan SH, George WO (1996) Improved SPRT and CUSUM procedures with compressed-limit Gauges. IIE Trans 28:489–496
Stoumbos ZG, Reynolds MR Jr (1997) Corrected diffusion theory approximations in evaluating properties of SPRT charts for monitoring a process mean. Nonlinear An 30:3987–3996
Reynolds MR Jr, Stoumbos ZG (1998) The SPRT chart for monitoring a proportion. IIE Trans 30:545–561
Stoumbos ZG, Reynolds MR Jr (2001) The SPRT control chart for the process mean with samples starting at fixed times. Nonlinear An 2:1–34
Li Y, Pu XL, Tsung FG (2009) Adaptive charting schemes based on double sequential probability ratio tests. Qual Reliab Eng Int 25:21–39
Corsini G, Dalle Mese E, Marchetti G, Verrazzani L (1985) Design of the SPRT for radar target detection. IEE Proceedings F 132:139–148
Bagchi TP (1992) Sequential tests to monitor lot attribute quality in the presence of inspection errors. Opsearch 29:165–183
Stefan A, Ali B, Ingvar C (1996) Quality monitoring in robotized welding using sequential probability ratio test. IEEE Region 10 Annual Int Conference 2:635–640
Yu FJ, Low CY, Cheng SS (2003) Design for an SPRT control scheme based on linguistic data. Int J of Prod Res 41:1299–1309
Kwon D, Azarian MH, Pecht MG (2008) Early detection of interconnect degradation using RF impedance and SPRT. Int Conf Prognostics and Health Management 1–8
Stoumbos ZG, Reynolds MR Jr (1996) Control charts applying a general sequential test at each sampling point. Sequential An 15:159–183
Stoumbos ZG, Reynolds MR Jr (1996b) Variable sampling rate control charts with sampling at fixed intervals. Proceedings of the Fifth Industrial Eng Res Conference 687–692
Ou YJ, Wu Z, Lee KM, Chen SL (2009) A highly effective control SPRT chart for monitoring process mean. Technical Report, School of Mechanical and Aerospace Engineering, Nanyang Technological University
Wu Z, Jiao JX, Yang M, Liu Y, Wang ZJ (2009) An enhanced adaptive CUSUM control chart. IIE Trans 41:642–653
Sparks RS (2000) Cusum charts for signalling varying location shifts. J Qual Technol 32:157–171
Reynolds MR Jr, Stoumbos ZG (2004) Should observations be grouped for effective process monitoring. J Quality Technol 36:343–366
Shu LJ, Jiang W (2006) A Markov chain model for the adaptive CUSUM control chart. J Qual Technol 38:135–147
Wu Z, Yang M, Jiang W, Khoo MBC (2008) Optimization designs of the combined shewhart-CUSUM control charts. Comput Stat Data An 53:496–506
Reynolds MR Jr, Stoumbos ZG (2004) Control charts and the efficient allocation of sampling resources. Technometrics 46:200–214
Reynolds MR Jr, Stoumbos ZG (2006) Comparisons of some exponentially weighted moving average control charts for monitoring the process mean and variance. Technometrics 48:550–567
Domangue R, Patch SC (1991) Some omnibus exponentially weighted moving average statistical process monitoring schemes. Technometrics 33:299–313
Wu Z, Tian Y (2005) Weighted-loss-function CUSUM chart for monitoring mean and variance of a prod process. Int J Prod Res 43:3027–3044
Yu KT, Sheu SH, Chen KS (2007) The evaluation of process capability for a machining center. Int J Adv Manuf Technol 33:505–510
Reynolds MR Jr, Amin RW, Arnold JC (1990) CUSUM charts with variable sampling intervals. Technometrics 32:371–384
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ou, Y., Wu, Z., Chen, S. et al. An improved SPRT control chart for monitoring process mean. Int J Adv Manuf Technol 51, 1045–1054 (2010). https://doi.org/10.1007/s00170-010-2675-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00170-010-2675-6