Abstract:  Under make-to-order (MTO) environment, in the small-and-medium-size manufacturing enterprises, the order fulfillment is affected by many certain and random factors such as processing time variation, urgent order insertion, machine failure, scrap and rework, waiting, and so on. Based on the assumption that each random factor has a known stochastic distribution, a model of estimating the order completion date is developed. With this model, order completion date can be obtained by simulation. Then, by considering the customer’s delivery requirement, order due date and price can be determined. Also, sensitivity analysis is done to understand the interrelations among the mean order completion date and the uncertain factors. Finally, suggestions are given for how to control the uncertain factors.

Key words: make-to-order (MTO), uncertainty, completion date estimation, due date