  The paper discusses how to evaluate the reliability of units produced by
different production lines. The procedure is based on selecting independent
random samples of units produced by different production lines and then
evaluating reliability functions for each group of units. The comparison
between these reliability functions at a given time allows manufacturing
experts to evaluate the effectiveness of production lines. A statistical
methodology has been taken based on the assumption that the lifetime of units
produced by each product line has a Weibull Gamma distribution. Then,
real-world data is used to illustrate the study's contribution to reliability
theory applications.
