Cloudy fuzzy inventory model under imperfect production process with demand dependent production rate

The aim of this article is an effort to initiate the cloudy fuzzy number in developing classical economic production lot-size model of an item produced in scrappy production process with fixed ordering cost and without shortages. Here, the market value of an item is cloudy fuzzy number and the production rate is demand dependent. In general, fuzziness of any parameter remains fixed over time, but in practice, fuzziness of parameter begins to reduce as time progresses because of collected experience and knowledge that motivates to take cloudy fuzzy number. The model is solved in a crisp, general fuzzy and cloudy fuzzy environment using Yager's index method and De and Beg's ranking index method and comparisons are made for all cases and better results obtained in the cloudy fuzzy model. The model is solved by dominance based Particle Swarm Optimization algorithm to obtain optimal decision and numerical examples and sensitivity analyses are presented to justify the notion.