Note on “Effects of Random Defective Rate and Imperfect Rework Process on Economic Production Quantity Model”

This paper considers the economic production quantity (EPQ) model with a random defective rate and an imperfect rework process. The assumption of perfect quality production condition of the classical EPQ model is unrealistic. Due to process deterioration or other factors, production of defective items is inevitable. This study assumes that the defective rate is a random variable and all items produced are inspected. The imperfect quality items fall into two groups, the repairable and the scrap. The reworking of the repairable defective items starts when the regular production process finishes in each cycle. The rework process is also assumed to be imperfect, with a random scrap rate. Since the scrap items are produced during a production run, it follows that the production cycle length is not a constant. The renewal reward theorem is utilized to cope with the variable cycle length. A mathematical model is developed to minimize the overall costs and to derive the optimal lot size for the imperfect quality EPQ model where shortages are not permitted. A numerical example is provided to demonstrate its practical usage.

[1]  Y. Chiu.  Determining the optimal lot size for the finite production model with random defective rate, the rework process, and backlogging , 2003 .

[2]  Meir J. Rosenblatt,et al.  Simultaneous determination of production cycle and inspection schedules in a production system , 1987 .

[3]  Leopoldo Eduardo Cárdenas-Barrón,et al.  The economic production quantity (EPQ) with shortage derived algebraically , 2001 .

[4]  M. K. Salameh,et al.  Economic production quantity model for items with imperfect quality , 2000 .

[5]  Steven Nahmias,et al.  Production and operations analysis , 1992 .

[6]  S. W. Chiu,et al.  Effects of random defective rate and imperfect rework process on economic production quantity model , 2004 .

[7]  Jerome S. Osteryoung,et al.  Use of the EOQ model for inventory analysis , 1986 .

[8]  Singa PWang Chiu,et al.  An economic production quantity model with the rework process of repairable defective items , 2003 .

[9]  P. A. Hayek,et al.  Production lot sizing with the reworking of imperfect quality items produced , 2001 .

[10]  Mohamed Ben-Daya,et al.  The economic production lot-sizing problem with imperfect production processes and imperfect maintenance , 2002 .

[11]  Xin Zhang,et al.  Joint lot sizing and inspection policy in an EOQ model with random yield , 1990 .

[12]  T.C.E. Cheng,et al.  An Economic Order Quantity Model with Demand-Dependent Unit Production Cost and Imperfect Production Processes , 1991 .

[13]  R L Schwaller.  EOQ UNDER INSPECTION COSTS , 1988 .

[14]  Meir J. Rosenblatt,et al.  Economic Production Cycles with Imperfect Production Processes , 1986 .

[15]  David F. Pyke,et al.  Inventory management and production planning and scheduling , 1998 .

[16]  Kun-Jen Chung.  Bounds for production lot sizing with machine breakdowns , 1997 .

[17]  Robert W. Grubbström,et al.  The EOQ with backlogging derived without derivatives , 1999 .