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Study on Implementing Control Charts Assuming Negative Binomial Distribution with Varying Sample Size in a Software Industry
Summary: [This abstract is based on the author's abstract.] Control charts based on Poisson distribution may not be appropriate for monitoring the number of defects. In such cases, the negative binomial is a viable alternative. Quality control personnel in an Indian software company who were using a control chart based on Shewhart�s principle to count defects were experiencing many false alarms. A control chart using negative binomial with varying sample size was devised, parameters were estimated, and control limits were proposed. This control chart greatly reduced the number of false alarms and was implemented as a standard practice.
- Topics: Sampling, Metrics
- Keywords: Sample size,Metrics,Negative binomial distribution,Poisson distribution,Control charts,Case study,False alarm rate (FAR),Design of control charts
- Author: Das, Nandini
- Journal: Software Quality Professional Magazine