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A note on two process adjustment models
Author(s) -
Castillo Enrique Del
Publication year - 1998
Publication title -
quality and reliability engineering international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 62
eISSN - 1099-1638
pISSN - 0748-8017
DOI - 10.1002/(sici)1099-1638(199801/02)14:1<23::aid-qre138>3.0.co;2-h
Subject(s) - statistical process control , process (computing) , computer science , compensation (psychology) , control (management) , process control , variable (mathematics) , point (geometry) , common cause and special cause , variation (astronomy) , econometrics , statistics , mathematics , artificial intelligence , psychology , mathematical analysis , geometry , psychoanalysis , operating system , physics , astrophysics
The idea of a process ‘adjustment’ has different connotations depending on whether one is talking from a statistical process control (SPC) or from an engineering process control (EPC) point of view. In SPC an adjustment implies the correction of some problem that has caused abnormal variation. The corrective action usually restores the process mean to a desired or ‘in‐control’ level. In EPC an adjustment means the compensation of some observed deviation by manipulating a control variable. This paper analyses two models proposed for process adjustment useful for understanding these and other important differences. One model is based on assumptions common in EPC applications, the other is based on assumptions common in SPC applications. Adjustment policies for each model are presented and contrasted. © 1998 John Wiley & Sons, Ltd.