Approximation of optimal order policy for deteriorating items with a linearly increasing demand

We consider the paper recently published in Optimization by Chung and Ting. They studied the economic ordering policy for deteriorating items with a linearly increasing demand. Their results contained two unnecessary propositions and one incomplete theorem. The purposes of this paper are threefold. First, we point out these drawbacks in their paper. Second, an approximated solution is offered by us. Third, we show the existence and uniqueness properties of our solution. A numerical example is given to illustrate the results.