4. Conclusions
This paper uses an analytic approach to examine the EOQ/EPQ inventory models with two backorder costs and derives
two lemmas and four useful theorems to obtain the optimal solution to both inventory models. Basically, this paper is not
only to overcome the shortcomings of Johnson and Montgomery [12] but also to improve Sphicas [13]. Finally, our analytic
solution procedure is complete and easy. It is important to remark that the EOQ/EPQ models analyzed in this paper are
deterministic. However, our solution procedure can be used in developing more complex inventory models.
Acknowledgments
The second author was supported partially by the School of Business and the Tecnológico de Monterrey research fund
numbers CAT128 and CAT185.