To settle the imperfect production process, an imperfect production system with fuzzy random deteriorating
process under allowable shortage is investigated. The economic production quantity(EPQ) model including shortage cost and fuzzy random rework cost is established. Based on the credibility theory, the expected average cost per unit time is derived, and then the properties of the cost function are revealed. The optimal production length which can minimize the expected average cost is proved to exist and be unique, and the upper and lower bounds of the optimal production time are determined. Bisection method for the optimal production length is designed. Finally, a numerical example is presented to show the effectiveness of the proposed model and illustrate the effects of the shortage cost, rework cost and the defective item ratio on the optimal production policy.