There are many service systems (especially in reservation systems, electronic commerce, in tasks synchronized directly with the Internet), where each task has to be executed in some fixed range of time. Exceeding the term is disadvantageous and causes additional penalties. Therefore, it is necessary to establish optimal sequence of tasks (which minimizes penalties) and its starting times. It am...

In this paper, we will present a new variant of genetic algorithm to solve optimization problems where the number of feasible solutions is very important. This approach consists on a hybrid algorithm between genetic algorithms introduced by J. Holland (1975) and dynamic programming method of R. Bellman (1957). Then we will apply this hybrid algorithm to solve a single machine scheduling problem...

For the purpose of solving the flexible job-shop scheduling problem (FJSP), an improved quantum genetic algorithm based on earliness/tardiness penalty coefficient is proposed in this paper. For minimizing the completion time and the job-shop cost, a simulation model was established firstly. Next, according to the characteristics of the due in production, a double penalty coefficient was designe...

We examine the problem of scheduling jobs, on a single processor to minimise the total earliness and tardiness costs about a common due date. Jobs belong to mutually exclusive families and a sequence independent setup task is required when processing switches from a job of one family to a job of another. We extend earlier results to obtain necessary optimal conditions for this problem. These ar...

Crossover operators that preserve common components can also preserve representation level constraints. Consequently, these constraints can be used to beneficially reduce the search space. For example, in flow shop scheduling problems with order-based objectives (e.g. tardiness costs and earliness costs), search space reductions have been implemented with precedence constraints. Experiments sho...

This paper addresses a one-machine scheduling problem in which the efficiency of the machine is not constant, that is the duration of a task is longer in badly efficient time periods. Each task has an irregular completion cost. Under the assumption that the efficiency constraints are time-periodic, we show that the special case where the sequence is fixed can be solved in polynomial time. The g...

This paper considers Just-In-Time Job-Shop Scheduling, in which each activity has an earliness and a tardiness cost with respect to a due date. It proposes a constraint programming approach, which includes a novel filtering algorithm and dedicated heuristics. The filtering algorithm uses a machine relaxation to produce a lower bound that can be obtained by solving a Just-In-Time Pert problem. I...

The problem of scheduling groups of jobs on a single machine under the group technology assumption is studied. Jobs of the same group are processed contiguously and a sequence independent setup time precedes the processing of each group. All jobs have a common fixed due date, which can be either unrestrictively large or restrictively small. The objective is to minimize the total weighted earlin...

Abstract Most Workload Control literature assumes that delivery performance is determined by tardiness related measures only. While this may be true for companies directly deliver to end-customers, make-to-stock or firms are part of supply chains, producing early often means large inventories in the finished goods warehouse penalties incurred downstream chain. Some earlier studies used a so-cal...

In one-machine scheduling, MIP time-indexed formulations are often used to provide very good lower bounds through Lagrangian relaxations. In order to get an improved lower bound, we add valid cuts to a time-indexed formulation and show we still have a Lagrangian relaxation that can be solved as a shortest path in a graph. Two branch-and-bound algorithms are then presented for the earliness-tard...