Perishable inventory system with postponed demands and negative customers.
In general, traditional production-inventory systems are based on a number of simplifying – but somewhat unrealistic – assumptions, including constant demand rate, constant holding cost, and instantaneous order replenishment. These assumptions have been individually challenged in numerous variations of production-inventory models. Finite production rate models, such as economic production quantity (EPQ) systems consider gradual order replenishment. Stock-dependent demand models assume the demand...
The notion of productivity of activities is introduced, its characterization is given and three special types of return functions are examined.