An analytic solution approach for the economic order quantity model with Weibull ameliorating items

While deterioration models consider the gradual reduction in quality and quantity of products over time, amelioration models assume the opposite. This paper is based on an earlier work by Hwang for finding an optimal economic order quantity solution for items subject to amelioration in a Weibull distribution. Hwang solved the problem with a graphical procedure. In this paper, a rigorous analytical solution approach is derived for cases with different shape parameters. A detailed numerical example is also presented to illustrate the optimality of the derived solution.