A Lean Six Sigma project is attempting to reduce inventory days. The Process Capability will be monitored as part of the Control Phase to track the sustainability of the improvement.
Which distribution type is best used for performing the Capability Analysis?
The Weibull distribution is the best choice for performing the Capability Analysis. In the Probability Plot for Inventory Days, the Weibull distribution shows a good fit with the data points mostly lying within the 95% confidence interval lines, indicating that it adequately models the process behavior. The other distributions, such as Normal, Exponential, and Logistic, do not fit the data as well based on their goodness-of-fit test results and visual inspection of the plots.
A is correct. In the Probability Plot for Weibull, most of the data is fitting inside the 95% confidence interval lines as compared to other plots.