EPQ model for imperfect items with inspection and inspection errors using Evidence theory and considering the time value of Money

Previous imperfect items inventory studies have mainly focused on developing cost-minimizing models that do not consider the time value of money and inflation rate. In practice, not only productions but inspection processes are often not perfect and certain. Thus, this paper represents an inventory model for imperfect items with qualitative inspection and inspection errors using Evidence theory and considering the time value of money. This model incorporates both imperfect production items and two-way inspection errors, i.e., Type-one inspection error of falsely screen out a proportion of no defects and disposing of them like defects and type-two inspection error of falsely not screening out a proportion of defect, thereby passing them on to customers, resulting in defect sales return. We also consider salvage, rework process, and one more stage of inspection, in which there are no inspection errors. Unlike previous studies, which considered inspection errors as constant and well-known, stochastic or fuzzy, this model involves inspection errors with the uncertainty of Evidence theory. Finally, a numerical example is provided to solve the presented inventory model using our proposed algorithm.

کلیدواژه ها:

Inventory System ، Inspection Error ، Customer return ، Evidence theory ، Time value of money