This paper addresses a hybrid flow shop scheduling problem with real-world constraints, and proposes a novel algorithm for its solution. We first discuss the distinguishing characteristics of nighttime and simultaneous work in the transformer manufacturing process. To solve the problem within a reasonable time, we propose a hybrid genetic algorithm. This algorithm combines the Nawaz–Enscore–Ham...

The multi-processor total tardiness problem (MPTTP) is an -hard scheduling problem, in which the goal is to minimise the tardiness of a set of jobs that are processed on a number of processors. Exact algorithms like branch and bound have proven to be impractical for the MPTTP, leaving stochastic local search (SLS) algorithms as the main alternative to find high-quality schedules. Among the avai...

Meeting due dates as a re ̄ ection of customer satisfaction is one of the scheduling criteria that is frequently encountered in today’s manufacturing environments. The natural quanti ® cation of this qualitative goal involves tardiness related measures. In this study, we consider the dynamic job shop scheduling problem with the weighted tardiness criterion. After we present a comprehensive liter...

In this researcha particle swarm optimization (PSO) algorithm is proposedfor no-wait flowshopsequence dependent setuptime scheduling problem with weighted earliness-tardiness penalties as the criterion ( | , | ∑ " ).The smallestposition value (SPV) rule is applied to convert the continuous value of position vector of particles in PSO to job permutations.A timing algorithm is generated to find t...

Various integer programming models have been proposed for sequencing problems. However, little is known about the practical value of these models. This paper reports a comparison of six different integer programming formulations of the single-machine total tardiness problem. We created a set of especially difficult test problems and attempted to solve them with each of the formulations, using C...

A customer who places a tentative order at a steel mill customarily receives a due-date quotation, namely the date by which the mill says that it will ship the order. The steel mill wants the due date to be early enough so that the customer won’t balk (withdraw the order), but late enough so that the probability of tardiness is low. This note obtains expressions for the tardiness probability at...

Production scheduling and preventive maintenance planning decisions are inter-dependent but most often made independently. Given that maintenance affects available production time and elapsed production time affects the probability of machine failure, this interdependency seems to be overlooked in the literature. We propose an integrated model that simultaneously determines production schedulin...

W e examine leadtime-quoting polices for minimizing average lead time subject to customer service constraints on fill rate, tardiness, or relative tardiness in simple systems with exponential and normal processing times. By studying the resulting safety leadtimes implied by each policy we gain insight into why some policies perform more robustly with respect to different measures of customer se...

Ant Colony Optimization is a relatively new meta-heuristic that has proven its quality and versatility on various combinatorial optimization problems such as the traveling salesman problem, the vehicle routing problem and the job shop scheduling problem. The paper introduces an Ant Colony Optimization approach to solve the problem of determining a job-sequence that minimizes the overall tardine...

We study the problem of scheduling unit-length interval-ordered tasks subject to unit-length communication delays with the objective of minimising the maximum tardiness. Without communication delays, this problem can be solved by a generalisation of an algorithm presented by Garey and Johnson. In this paper, an algorithm is presented that considers unit-length communication delays and construct...