The control charts are widely used to control the process stability, and then analyse the ‘in-control’ data in the statistical process control. However, an ‘in-control’ process is not enough since it can produce non-conforming or out of specification products. Process capability indices, like Cp , Cpu , Cpl and Cpk , have been proposed to make decisions on how well the process meets specifications in practice. These indices can not be straightforwardly used for illustrating and analysing the multi-process products. Hence, the multi-process performance analysis chart (MPPAC) has been proposed. Nevertheless, the MPPAC approach is not reliable since sampling errors are ignored, and PCAC is only just suitable for full inspection. To overcome these shortcomings, this paper aims to develop an advanced multi-process performance analysis chart (AMPPAC) with process capability zones as well as taking into account interval estimates of these indices for precisely measuring an entire product composed of symmetric tolerances, larger-the-better and smaller-the-better characteristics. Besides, the issue about independent processes has been proposed by Chen et al . (Chen, K.S., Huang, M.L. and Li, R.K., Process capability analysis for an entire product. Int. J. Prod. Res., 2001, 39(17), 4077–4087.), and the solution about dependent processes will be provided in this paper. Thus, the AMPPAC can reliably and appropriately assess the multi-process performance and provide chances for continuous improvement on the manufacturing process.
No takes yet. Share an insight, caveat, or question.
Chen et al. (2006) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: