This paper addresses minimizing Total Weighted Earliness/Tardiness (TWET) of jobs in a Flexible Job Shop (FJS) problem. The FJS problem is an extension of the classical Job Shop (JS) problem that implies each operation may be assigned to alternative available machines. So, a job may have alternative routing. The FJS problem with a TWET criterion is modeled as a mixed integer programming. The mo...

In the scheduling problem addressed in this note we have to determine: (i) the job sequence, (ii) the (common) due-date, and (iii) the location of a rate modifying (maintenance) activity. Jobs scheduled before (after) the due-date are penalized according to their earliness (tardiness) value. The processing time of a job scheduled after the maintenance activity decreases by a job-dependent facto...

We propose a column generation based exact decomposition algorithm for the problem of scheduling n jobs with an unrestrictively large common due date on m identical parallel machines to minimize total weighted earliness and tardiness. We rst formulate the problem as an integer program, then reformulate it, using Dantzig-Wolfe decomposition, as a set partitioning problem with side constraints. B...

This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d). It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the...

In this study, we consider single-machine scheduling problems with past-sequence-dependent (denoted by psd) setup times in which the of jobs are proportional to length already processed jobs. Under common (CON) and slack (SLK) due-date assignment methods, prove that weighted sum earliness, tardiness minimization remains polynomially solvable. We also give some extensions for psd times.

OBJECTIVE To determine whether sales of electrolyte products contain a signal of outbreaks of respiratory and diarrheal disease in children and, if so, how much earlier a signal relative to hospital diagnoses. DESIGN Retrospective analysis was conducted of sales of electrolyte products and hospital diagnoses for six urban regions in three states for the period 1998 through 2001. MEASUREMENT...

In the Weighted Total Acquisition problem (WTA) on a weighted graph G (only positive non-zero weights), vertex v can acquire total weight of neighbour u if and only current is at least that u. The new then zero, sum weights just before acquisition. Over all possible acquisition sequences in with function w, minimum number vertices end denoted by at(G,w). Given G, weighting an integer k?1, WTA a...

In this paper, we propose n-jobs to be processed on Single Machine Scheduling Problem (SMSP) involving fuzzy processing time and fuzzy due dates. The different due dates for each job be considered which meet the demand of customer with more satisfaction level. The main objective of this paper is the total penalty cost to be minimum in the schedule of the jobs on the single machine. This cost is...

The aim of this paper is to solve a problem on scheduling with earliness and tardiness costs using constraint programming approach, and to compare the results with the ones from the original timed automata approach. The case study, a production of lacquers, includes some real life features like operating hours or changeover times. Considering the earliness and tardiness costs of the case study,...