An EMQ model with price and time dependent demand under the effect of reliability and inflation

The paper deals with an economic manufacturing quantity (EMQ) model for the selling price and the time dependent demand pattern in an imperfect production process. Due to long-run, machine breakdown may occur, as a result, the system may shift to out-of-control state from in-control state and production systems begin to produce imperfect quality items. The production of imperfect items increases with time. All imperfect quality items are reworked at a fixed cost to restore these to its original quality. To reduce the production of the imperfect quality items, we consider reliability as a decision variable along with the development cost and the production cost as a function of reliability. The profit function is maximized by Euler-Lagrange formula. The numerical example, sensitively analysis, and graphical illustrations are given to illustrate the model. (C) 2014 Elsevier Inc. All rights reserved.