This paper describes a new approach for solving disjunctive temporal problems such as the open shop and job shop scheduling domains. Much previous research in systematic search approaches for these problems has focused on developing problem specific constraint propagators and ordering heuristics. Indeed, the common belief is that many of these problems are too difficult to solve without such do...

Job-shop manufacturing environment requires planning of schedules for the systems of low-volume having numerous variations. For a job-shop scheduling, ‘k’ number of operations and ‘n’ number of jobs on ‘m’ number of machines processed through an assured objective function to be minimized (makespan). This paper presents a capable genetic algorithm for the job-shop scheduling problems among opera...

This paper presents a comparison study of the computational complexity of the general job shop protocol and the ow line protocol in a exible manufacturing system. It is shown that 2 a certain representative problem of nding resource invariants is NP-complete in the case of the job shop, while in the ow line case it admits a closed-form solution. The importance of correctly selecting part ow and...

Job shop scheduling (JSS) is a problem which involves an assignment of a set of tasks to the machines in a predefined sequence in order to optimize one or more objectives considering job performance measures of the system. It’s a multi-objective, multi-criteria optimization problem. A job shop environment consists of ‘n’ jobs. Each job has a given machine routine in which some machines could be...

A model combining Discrete Event System (DES) and Multi-Agent System (MAS) is proposed to simulate a real-time job shop so that it can work as a test bed to systematically study the performance of control rules and algorithms in dynamic job shop scheduling. A definition of a generic job shop is given considering dynamic events, shop floor layout and the Material Handling System (MHS). It is fir...

Scheduling is a scientific domain concerning the allocation of limited tasks over time. The goal of scheduling is to maximize (or minimize) different criteria of a facility as makespan, occupation rate of a machine, total tardiness ... In this area, scientific community usually group the problem with, on one hand the system studied, defining the number of machines (one machine, parallel machine...

In this paper we present a linear time approximation scheme for the job shop scheduling problem with fixed number of machines and fixed number of operations per job. This improves on the previously best 2 + ǫ, ǫ > 0, approximation algorithm for the problem by Shmoys, Stein, and Wein. Our approximation scheme is very general and it can be extended to the case of job shop scheduling problems with...

The general job-shop scheduling problem is known to be extremely hard. We describe a GA approach which produces reasonably good results very quickly on standard benchmark job-shop scheduling problems, better than previous eeorts using genetic algorithms for this task, and comparable to existing conventional search-based methods. The representation used is a variant of one known to work moderate...

The general job-shop scheduling problem is known to be extremely hard. We describe a GA approach which produces reasonably good results very quickly on standard benchmark job-shop scheduling problems, better than previous eeorts using genetic algorithms for this task, and comparable to existing conventional search-based methods. The representation used is a variant of one known to work moderate...

This paper presents and evaluates an order release decision rule in a job-shop, based on the input-output control concept. The order release mechanism is part of a global decision-making scheme that includes four main decisions: accept/reject orders, define the order’s due date, release the accepted jobs and dispatch it on the shop floor. This paper also presents an evaluation of two acceptance...