Estimating total and specific process capability indices in three-stage processes with measurement errors. Issue 15 (13th October 2018)

• Record Type: Journal Article
• Authors: Nikzad, Erfaneh; Amiri, Amirhossein; Amirkhani, Farzad
• Is Part Of: Journal of statistical computation and simulation. Volume 88:Issue 15(2018)
• Page Start: 3033
• Page End: 3064
• Publication Date: 2018-10-13
• Subjects: Three-stage processes -- cascade property -- measurement errors -- total process capability index -- specific process capability index; Mathematical statistics -- Data processing -- Periodicals; Digital computer simulation -- Periodicals; 519.5028505
• DOI: 10.1080/00949655.2018.1498096
• Languages: English
• ISSNs: 0094-9655

Abstract

ABSTRACT: In multistage processes, two kinds of process capability indices (specific and total process capability indices) are defined in each stage. The total process capability index calculates the capability of each stage when it is affected by the previous stages and the specific process capability index calculates the capability of the stage when the effects of the previous stages are eliminated. Process capability indices in multistage processes are proposed under the assumption of no measurement errors. However, sometimes this assumption may be violated and leads to misleading interpretations. In this paper, the effects of measurement errors on the specific and total process capability indices in the second and third stages of the three-stage processes are statistically analysed. In addition, the effects of the measurement errors on the bias and the mean square error value of the total and specific process capability indices in the second and third stages are studied. Finally, the effects of the measurement errors on the specific and total process capability indices are shown through a numerical example.