SYNOPTIC ABSTRACT
In this research article, a wholesaler-retailer supply chain model is developed for a seasonal deteriorating item where demand of the item increases with time at the beginning of season, reaches a maximum level, and then decreases gradually to normal demand at the end of the season. A retailer introduces some promotional cost to boost the base demand of the item. The demand of the item also depends on the unit selling price. In the case of any shortages, the demand is partially backlogged. It is found that if a wholesaler contributes a portion of promotional cost, then joint profit, as well as individual profit, increases. The supply chain model is also analyzed in an imprecise environment when different inventory parameters are fuzzy in nature. In this case, individual and channel profits become fuzzy in nature. As optimization of a fuzzy objective is not well defined, following the credibility measure of the fuzzy event, an approach is proposed for a comparison of fuzzy objectives and a particle swarm optimization (PSO) algorithm is used to identify marketing decisions. Models are illustrated with numerical examples.