78 Int. J. Operational Research, Vol. 11, No. 1, 2011 Copyright © 2011 Inderscience Enterprises Ltd. Two-warehouse fuzzy inventory model under the conditions of permissible delay in payments S.R. Singh* Department of Mathematics, D.N. College, Meerut (UP), India E-mail: shivrajpundir@gmail.com *Corresponding author Neeraj Kumar Department of Applied Science, IIMT Engineering College, Meerut (UP), India E-mail: neerajkapil99@yahoomail.com Rachna Kumari Department of Mathematics, Meerut College, Meerut (UP), India E-mail: kumarn_inde@yahoo.com Abstract: In this paper, a two-warehouse inventory model under the conditions of permissible delay in payments in fuzzy environment is developed. A rented warehouse is used when the ordering quantity exceeds the limited capacity of the owned warehouse. During the permissible delay period, no interest is charged by the supplier, but beyond this period interest is charged under the terms and conditions agreed upon and, moreover, interest can be earned on the revenue received during the credit period. Here, we have discussed four different cases to represent realistic situations of market: (1) when the inventory system has both the warehouse facilities, (2) when the owned warehouse has large capacity to store the inventory, (3) when simple EOQ model of single storage system and (4) when one does not wish to take RW services and OW has unlimited capacity. Finally, numerical example is given to illustrate feasibility of the model. Keywords: inventory; two-warehouse system; permissible delay; fuzzy environment. Reference to this paper should be made as follows: Singh, S.R., Kumar, N. and Kumari, R. (2011) ‘Two-warehouse fuzzy inventory model under the conditions of permissible delay in payments’, Int. J. Operational Research, Vol. 11, No. 1, pp.78–99. Biographical notes: S.R. Singh is an Associate Professor in the Department of P.G. study and Research in Mathematics in D.N. (P.G.) College, Meerut (UP), India. His PhD is from C.C.S. University, Meerut (UP), India. His research