Average tardiness

Service level constraints Commonly used service level constraints include an upper bound on (1) the fraction (or percentage) of orders which are completed after their due dates, (2) the average tardiness, and (3) the average order flow time. 

One of the earliest papers that studies DDM is by Conway [27]. He considers four due date policies, CON, NOP, TWK and RND, and tests the performance of nine priority dispatching rules for each of these policies in a job shop. For the objective of minimizing average tardiness, the author finds that under FCFS sequencing, the four due date policies exhibit similar, mediocre... 

The first two of these rules are parametric and the parameters a and (3 are chosen (based on simulation experiments) such that the service level constraints are satisfied. These rules apply to both problems I and II. The third and fourth rules set the shortest possible due date at any time to satisfy the service level constraints of the maximum fraction of tardy jobs and the maximum average tardiness, and apply to problems I and II, respectively. The proposed due date management policies use these rules with SPT sequencing between different classes, and FCFS sequencing within each class. 

A major problem is estimation of the weak collision factor (Troe, 1977b, 1979 Quack and Troe, 1977a Tardy and Rabinovitch, 1977 Endo, Glanzer, and Troe, 1979). This quantity can be related to the average energy transferred per collision by (Troe, 1977a)... 

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