The present study is concerned with the cost modeling of an inventory system with perishable multi-items having stock dependent demand rates under an inflationary environment of the market. The concept of permissible delay is taken into account. The study provides the cost analysis of inventory system under the decision criteria of time value of money, inflation, deterioration, and stock dependent demand. Numerical illustrations are derived from the quantitative model to validate the results. The cost of inventory and optimal time are also computed by varying different system parameters. The comparison of these results is facilitated by computing the results with neurofuzzy results. 1. Introduction Inflation is a very common scenario of a dynamic market which affects a common man and the decision makers equally. The term inflation refers to the increment in the rates of the goods. Most of the inventory models, developed so far, did not include the inflation and time value of the money as parameters of the system. But, during the past two decades, a sudden downfall in the market caused highly inflated rates and decision makers felt the need of considering the inflation an integrated part of an inventory model. There are many items which are subject to decay with respect to time. The concept of deterioration has been incorporated by some researchers in different frameworks (cf. [1–3]). The management of inventory emphasizing on time dependent deterioration with salvage value was discussed by Mishra and Shah [4]. Jain et al. [5] considered the concept of deterioration to develop a deterministic production inventory model with time-varying demand. Manna et al. [6] developed an EOQ model for noninstantaneous deteriorating items. The concept of exponential deterioration was considered by Mahata [7] to develop an EPQ-based inventory model. Xiao and Xu [8] discussed a supply chain with deteriorating items for a vendor managed inventory. Wang et al. [9] optimized a seller’s credit period in a supply chain for deteriorating items. Some notable works in the direction of inventory models with time value of money along with inflation are due to Bose et al. [10], Moon and Lee [11], Chang [12]. Singh and Jain [13] developed a model to study the supplier credits in an inflationary environment when reserve money was available. An inventory model by considering the concepts of inflation, deterioration, and permissible delay in the payments was studied by Jain and Chauhan [14]. Sarkar and Moon [15] analyzed an EPQ model by incorporating the effect of inflation for an
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