Dispatching rules are widely used to dynamically schedule the operations in a shop. Their efficiency depends on the performance criteria of interest. One of the most important objectives to deal with in a manufacturing system is the tardiness which can be measured through several performance measures. This paper proposes an effective procedure to estimate the first two central moments (i.e., th...

We consider a scheduling problem in which the criterion for assigning due dates is to make them as tight as possible, while the criterion for sequencing jobs is to minimize their tardiness. Because these two criteria conflict, we examine the trade-off between the tightness of the due dates and the tardiness of the jobs. We formulate a version of this trade-off in the case of a stochastic single...

We consider uniform parallel machine scheduling problems with unit-length jobs where every job is only allowed to be processed on a specified subset of machines. We develop efficient methods to solve problems with various objectives, including minimizing a total tardiness function, a maximum tardiness function, total completion time, the number of tardy jobs, the makespan, etc.

In this article we answer the complexity question of two dual criteria scheduling problems which had been open for a long time. Both problems are single machine scheduling problems and both have the number of tardy jobs as the primary criterion. However, the first problem has the total completion time and the second one has the total tardiness as the secondary criterion. We show that both probl...

In this paper, we address the problem of load selection and pickup-dispatching of multiple-load AGVs. Various load-selection rules and pickup-dispatching rules are proposed and studied. The objective of this study is twofold. We want to understand not only the performance of load-selection rules and pickup-dispatching rules in two performance criteria—throughput and tardiness, but also the effe...

Two single machine scheduling problems with fuzzy processing times and fuzzy due dates are considered. In both we define the fuzzy tardiness of a job in a given sequence as a fuzzy maximum of zero and the difference between the fuzzy completion time and the fuzzy due date of this job. In the first problem we minimize the maximal expected value of a fuzzy tardiness and in the second we minimize ...

The job shop scheduling problem (JSP) is one of the most difficult problems in traditional scheduling because any job consists of a set operations and also any operation processes by a machine. Whereas the operation is placed in the machine, it is essential to be considering setup times that the times strongly depend on the various sequencing of jobs on the machines. This research is developed ...

This paper deals with the permutation flowshop scheduling problem time lags constraints to minimize total weighted tardiness criterion by using Branch and Bound algorithm. A new lower bound was developed for problem. The computational experiments indicate that proposed algorithm provides good solution in terms of quality requirements.