1,099 research outputs found
A survey of scheduling problems with setup times or costs
Author name used in this publication: C. T. NgAuthor name used in this publication: T. C. E. Cheng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Single-machine scheduling of multi-operation jobs without missing operations to minimize the total completion time
Author name used in this publication: T. C. E. ChengAuthor name used in this publication: C. T. Ng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Scheduling in an assembly-type production chain with batch transfer
Author name used in this publication: T. C. E. Cheng2006-2007 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
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An intelligent manufacturing system for heat treatment scheduling
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research is focused on the integration problem of process planning and scheduling in steel heat treatment operations environment using artificial intelligent techniques that are capable of dealing with such problems.
This work addresses the issues involved in developing a suitable methodology for scheduling heat treatment operations of steel. Several intelligent algorithms have been developed for these propose namely, Genetic Algorithm (GA), Sexual Genetic Algorithm (SGA), Genetic Algorithm with Chromosome differentiation (GACD), Age Genetic Algorithm (AGA), and Mimetic Genetic Algorithm (MGA). These algorithms have been employed to develop an efficient intelligent algorithm using Algorithm Portfolio methodology. After that all the algorithms have been tested on two types of scheduling benchmarks.
To apply these algorithms on heat treatment scheduling, a furnace model is developed for optimisation proposes. Furthermore, a system that is capable of selecting the optimal heat treatment regime is developed so the required metal properties can be achieved with the least energy consumption and the shortest time using Neuro-Fuzzy (NF) and Particle Swarm Optimisation (PSO) methodologies. Based on this system, PSO is used to optimise the heat treatment process by selecting different heat treatment conditions. The selected conditions are evaluated so the best selection can be identified. This work addresses the issues involved in developing a suitable methodology for developing an NF system and PSO for mechanical properties of the steel.
Using the optimisers, furnace model and heat treatment system model, the intelligent system model is developed and implemented successfully. The results of this system were exciting and the optimisers were working correctly
Deterministic Assembly Scheduling Problems: A Review and Classification of Concurrent-Type Scheduling Models and Solution Procedures
Many activities in industry and services require the scheduling of tasks that can be concurrently executed, the most clear example being perhaps the assembly of products carried out in manufacturing. Although numerous scientific contributions have been produced on this area over the last decades, the wide extension of the problems covered and the lack of a unified approach have lead to a situation where the state of the art in the field is unclear, which in turn hinders new research and makes translating the scientific knowledge into practice difficult.
In this paper we propose a unified notation for assembly scheduling models that encompass all concurrent-type scheduling problems. Using this notation, the existing contributions are reviewed and classified into a single framework, so a comprehensive, unified picture of the field is obtained. In addition, a number of conclusions regarding the state of the art in the topic are presented, as well as some opportunities for future research.Ministerio de Ciencia e Innovación español DPI2016-80750-
Customer order scheduling on a single machine with family setup times: complexity and algorithms
Cataloged from PDF version of article.We consider a situation where C customers each order various quantities (possibly zero in some cases) of products from
P different families, which can be produced on a continuously available machine in any sequence (requiring a setup whenever
production switches from one family to another). We assume that the time needed for a setup depends only on the
family to be produced immediately after it, and we follow the item availability model (which implies that all units are ready
for dispatch as soon as they are produced). However, an order is shipped only when all units required by a customer are
ready. The time from the start (time zero) to the completion of a customer order is called the order lead time. The problem,
which restates the original description of the customer order scheduling problem, entails finding a production schedule that
will minimize the total order lead time. While this problem has received some attention in the literature, its complexity
status has remained vexingly open. In this note, we show for the first time that the problem is strongly NP-hard. We proceed
to give dynamic programming based exact solution algorithms for the general problem and a special case (where C is
fixed). These algorithms allow us to solve small instances of the problem and understand the problem complexity more
fully. In particular, the solution of the special case shows that the problem is solvable in polynomial time when C is fixed.
2006 Elsevier Inc. All rights reserved
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