AbstractA linear-programming model to find the optimal‘CON due-date’is considered fornindependent jobs to be processed on a single machine. The term‘CON due-date’stands for constant-allowance due-date, where each job receives exactly the same due-date. The measure of performance considered is a more generalized version of similar problems studied earlier. Duality theory is used to obtain an optimal solution. Some earlier studies are shown to be special cases of the model studied in this paper. Numerical examples are presented for better understanding.