In a recent paper, Chang and Dye  developed an economic order quantity model for deteriorating items with exponential time-continuous demand and parti2l backlogging. In this note, the model of Chang and Dye  is reconsidered. A further extended model is developed for a general continuous time-varying demand. We find that under the assumptions of the Chang and Dye , the optimal procedure is independent from the form of the demand rate. We have also shown that it gives the global minimum.
International Journal of Information and Management Sciences 12(4), pp.55-60