Estimating Process Capability Indices Using Univariate g and h Distribution

Document Type : Research Paper


SQC&OR unit, Indian Statistical Institute, Kolkata, India


Process capability of a process is defined as inherent variability of a process which is running under chance cause of variation only. Process capability index is measuring the ability of a process to meet the product specification limit. Generally process capability is measured by 6 assuming that the product characteristic follows Normal distribution. In many practical situations the product characteristics do not follow normal distribution. In this paper, we describe an approach of estimating process capability assuming generalised g and h distribution proposed by Tukey.


Main Subjects

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  • Receive Date: 11 March 2010
  • Revise Date: 16 August 2010
  • Accept Date: 17 November 2010
  • First Publish Date: 01 July 2011