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.

We study the parallel machine scheduling problem with release dates and we consider several “min-sum” objective functions including total weighted tardiness, total tardiness, total weighted completion time and total completion time. We describe several lower bounds for these problems, most of them being original ones. We provide experimental results to compare these lower bounds according to th...

Two optimal algorithms, MTA* and MT-RBA*, are presented to find the optimal yard crane (YC) job sequence for serving a fleet of vehicles for delivery and pickup jobs with scheduled deadlines and predicted vehicle arrival times. The objective is to minimize the total tardiness of incoming vehicle jobs. This is important for minimizing vessel turnaround time. In the search for an optimal job sequ...

In this paper we study the single machine total tardiness problem. We first identify some optimality properties based on which a special case with a given number of distinct due dates is proved polynomially solvable. The results are then extended to the case with release dates. 2004 Published by Elsevier B.V.

We approximate optimal solutions to the Flexible Job-Shop Problem by using dispatching rules discovered through Genetic Programming. While Simple Priority Rules have been widely applied in practice, their efficacy remains poor due to lack of a global view. Composite Dispatching Rules have been shown to be more effective as they are constructed through human experience. In this work, we employ s...

A single machine scheduling problem is described which covers earliness costs, tardiness costs and setup costs. Setups are needed whenever a switch is made to a job of another product family. All jobs within the same product family have the same processing time. Besides setup costs also setup times are involved. Idle time is allowed, preemption is not allowed. Both a mixed integer programming f...

We present a simple result in single-machine scheduling theory. Namely, the number of tardy jobs in a sequence which is optimal with respect to total tardiness is no greater than the number of tardy jobs in the earliest due date sequence. This provides a bound for solutions to the total tardiness problem on a single machine found using branch and bound, dynamic programming or the decomposition ...

Four heuristic algorithms are developed for solving the generalized version of tardiness flow shop problems. We consider the generalized tardiness flow shop model with minimization of the total tardiness as its performance measure. We modify the concept of cost over time (COVERT) for the generalized version of the flow shop tardiness model and employ this concept for developing four algorithms....