Title: Fuzzy EOQ models with ramp type demand rate, partial backlogging and time dependent deterioration rate

Authors: Ravi Shankar Kumar; S.K. De; A. Goswami

Addresses: Department of Mathematics, Indian Institute of Technology, Kharagpur 721 302, West Bengal, India. ' Department of Mathematics, Midnapore College, West Midnapore, West Bengal 721102, India. ' Department of Mathematics, Indian Institute of Technology, Kharagpur 721 302, West Bengal, India

Abstract: In this study, a fuzzy inventory model has been discussed for two cases: model start with no shortages; model start with shortages. Demand rate is of three folded ramp-type time dependent, deterioration rate of the item is time dependent(Weibull) and shortages are partially backlogged. For real situation, we have assumed the backlogging rate and all the cost coefficients as trapezoidal fuzzy number and defuzzification is made with the help of Function Principle and Graded Mean Integration Representation (GMIR) method. Finally using calculus, we have optimised the total cost function. The solution procedure is illustrated with the help of numerical examples.

Keywords: inventory modelling; ramp type demand; partial backlogging; trapezoidal fuzzy numbers; function principle; optimisation; fuzzy EOQ; economic order quality; time dependent deterioration; deterioration rate.

DOI: 10.1504/IJMOR.2012.048927

International Journal of Mathematics in Operational Research, 2012 Vol.4 No.5, pp.473 - 502

Published online: 23 Dec 2014 *

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