Abstract
In this paper, economic production quantity(EPQ)models for break-
able or deteriorating items are developed with time dependent linear
variable demands. Here rate of production and holding cost are time
dependent and unit production cost is a function of both production
reliability indicator and production rate. Set-up cost is also partially
production rate dependent. Here two models are developed in optimal
control framework considering the effect of time value of money and
inflation. Shortages are allowed for both the models. The problems
are solved using Eulers-Lagrangian function based on variational
calculus and applying generalized reduced gradient method using
LINGO 13.0 software to determine the optimal reliability indicator (r)
and then corresponding production rates and total profits. Numerical
experiments are performed for both the models to illustrate the models
both numerically and graphically.