Abstract
The present paper proposes a due-date estimation method for customer orders with unfixed specifications. Such customer orders are defined as those whose products are partially composed of undecided components. The process of clarifying the undecided components is modeled without the loss of generality. Then, a modified version of the due-date estimation method, which has been investigated by the author and others in the last decade, is shown to be able to estimate due dates and fulfill them for all customer orders, including those with unfixed specifications. It is also shown that the desirable specification clarifying dates are obtained from the updated production schedule generated by the due-date estimation, which information is valuable not only for the manufacturer but also the customers holding unfixed specifications to execute efficient production activities.
