فرایند تولید ناقص در یک حجم مدل موجود انعطاف پذیر

This paper hypothesizes an imperfect production/inventory system where the items produced are a mixture of perfect and imperfect quality. Some of the imperfect quality items can be sold at a reduced selling price. The unit production cost is taken to be a function of the finite production rate which is treated as a decision variable. The mathematical expression for the expected profit function is derived and it is maximized subject to different constraints of the system using Interior Penalty Function Method for Constrained Optimization, the algorithm of which is given. The solution procedure is illustrated with the help of numerical examples. The sensitivity of each variable to changes in the values of the parameters of the system is examined. Lastly, various issues conforming the system are discussed.

It is important to a supply manager of any modern organization to control and maintain the inventories of perfect and imperfect quality products. In the Classical Economic Production Lot Size (EPLS) model, the amount produced is available at a constant rate. The rate of production is assumed to be predetermined and inflexible ( Hax and Candea, 1984). According to Schweitzer and Seidmann (1991), machine production rates can easily be changed. Empirical observations indicate that as the production-run-time increases, thereby the production system starts producing imperfect units as well. Some imperfect items are sold in the market by reducing selling price per unit and the rest of the imperfect items remain unsold. This type of production system usually occurs in many industries. The logistic diagram of the physical scenario is shown in Fig. 1.