In this paper, the single-machine scheduling problems under common and slack due date assignments are studied, where actual processing time of job needs to consider some factors, such as convex resource allocation, maintenance activity, learning effects. The goal study is find optimal sequence, activity location, allocation (flow allowance). objective function (1) minimize sum cost (including w...

The General Scheduling Problem (GSP) generalizes scheduling problems with sum of cost objectives such as weighted flow time and weighted tardiness. Given a set of jobs with processing times, release dates, and job dependent cost functions, we seek to find a minimum cost preemptive schedule on a single machine. The best known algorithm for this problem and also for weighted flow time/tardiness i...

This paper investigates common (slack) due-date assignment single-machine scheduling with controllable processing times within a group technology environment. Under linear and convex resource allocation functions, the cost function minimizes (including weighted sum of earliness, tardiness, assignment, where weights are position-dependent) resource-allocation costs. Given some optimal properties...

FACULTY OF SOCIAL, HUMAN AND MATHEMATICAL SCIENCES Mathematical Sciences Doctor of Philosophy THE VEHICLE ROUTING PROBLEM WITH RELEASE AND DUE DATES: FORMULATIONS, HEURISTICS AND LOWER BOUNDS Benjamin C. Shelbourne A novel extension of the classical vehicle routing and scheduling problem is proposed that integrates aspects of machine scheduling into vehicle routing. Associated to each customer ...

Appropriate scheduling and sequencing of tasks on machines is one of the basic and significant problems that a shop or a factory manager encounters with it, this is why in recent decades extensive researches have been done on scheduling issues. A type of scheduling problems is just-in-time (JIT) scheduling and in this area, motivated by JIT manufacturing, this study investigates a mathematical ...

In this paper we study the problem of deciding at what times to schedule patients when there are emergency arrivals following a non-stationary Poisson process. The service times can be any given distribution. The objective function consists of a weighted sum of the waiting times, idle time and tardiness. We prove that this objective function is multimodular, and then use a local search algorith...

Scheduling problems are important NP-hard problems. Genetic algorithms can provide good solutions for such optimization problems. In this paper, we present a genetic algorithm to solve the single machine total weighted tardiness scheduling problem, which is a strong NP-hard problem. The algorithm uses the natural permutation representation of a chromosome, heuristic dispatching rules combined w...

We present a new mathematical model for a permutation flowshop scheduling problem with sequence-dependent setup times considering minimization of two objectives, namely makespan and weighted mean total earliness/tardiness. Only small-sized problems with up to 20 jobs can be solved by the proposed integer programming approach. Thus, an effective multi-objective immune system (MOIS) is specially ...