ABSTRACT
The economic production quantity (EPQ) model for delayed deteriorating items considering two-phase production periods, exponential demand rate and linearly increasing function of time holding cost is proposed to solve a production problem similar to the one caused by the Covid-19 pandemic. Without shortages, the necessary and sufficient conditions for optimality of this model are characterized through a theorem and lemmas while a solution methodology based on differential calculus is adopted. This paper determines the best replenishment cycle length corresponding to the optimal total variable cost and production quantity of imperfect production industry. To illustrate this model, a numerical experiment is conducted. The results demonstrate that a higher carrying charge decreases the production quantity and a longer demanding period decreases the total variable cost of an industry with a distracted production period. Finally, managerial insights are discussed using sensitivity analysis and future research directions are exposed.
ABSTRACT
This model investigates the optimal time at which a production cycle should be stopped and then resumed in a production-inventory system, in order to keep shortages under control. This study considers a perishable item that decays at a constant rate. Year 2020 has seen a sudden surge in the demand of masks, PPEs, etc. to combat COVID-19. Such demand, which follows an exponential distribution, has been considered. The production rate is taken to be a linear function of demand, so as to cope up with an exponential market demand. The holding cost is taken to be a linear function of time. Shortages are allowed to occur and are completely backlogged. This model handles variable production, variable demand and variable holding cost simultaneously. The model is illustrated by a numerical example. Sensitivity analysis is carried out and has been detailed with the help of graphs. A case study has also been done. Copyright © 2022 Inderscience Enterprises Ltd.