Evolution has provided a source of inspiration for algorithm designers since the birth of computers. The resulting field, evolutionary computation, has been successful in solving engineering tasks ranging in outlook from the molecular to the astronomical. Today, the field is entering a new phase as evolutionary algorithms that take place in hardware are developed, opening up new avenues towards autonomous machines that can adapt to their environment. We discuss how evolutionary computation compares with natural evolution and what its benefits are relative to other computing approaches, and we introduce the emerging area of artificial evolution in physical systems.

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From evolutionary computation to the evolution of things

In this paper we give an overview of recent developments in the field of modeling deterministic single-level dynamic lot sizing problems. The focus of this paper is on the modeling of various industrial extensions and not on the solution approaches. The timeliness of such a review stems from the growing industry need to solve more realistic and comprehensive production planning problems. First, several different basic lot sizing problems are defined. Many extensions of these problems have been proposed and the research basically expands in two opposite directions. The first line of research focuses on modeling the operational aspects in more detail. The discussion is organized around five aspects: the set ups, the characteristics of the production process, the inventory, demand side and rolling horizon. The second direction is towards more tactical and strategic models in which the lot sizing problem is a core substructure, such as integrated production-distribution planning or supplier selection. Recent advances in both directions are discussed. Finally, we give some concluding remarks and point out interesting areas for future research.

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Modeling Industrial Lot Sizing Problems: A Review

Single item lot sizing problems

Disaster relief presents many unique logistics challenges, with problems including damaged trans- portation infrastructure, limited communication, and coordination of multiple agents. Central to disaster relief logistics is the distribution of life-saving commodities to beneficiaries. Operations research models have potential to help relief agencies save lives and money, maintain standards of humanitarianism and fairness and maximize the use of limited resources amid post-disaster chaos. Through interviews with aid organizations, reviews of their publications, and a literature review of operations research models in transportation of relief goods, this paper provides an analysis of the use of such models from the perspective of both practitioners and academics. With the complexity of disaster relief distribution and the relatively small number of journal articles written on it, this is an area with potential for helping relief organizations and for tremendous growth in operations research.

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Disaster relief routing: Integrating research and practice

This paper presents a review of four decades of research on dynamic lot-sizing with capacity constraints. We discuss both different modeling approaches to the optimization problems and different algorithmic solution approaches. The focus is on research that separates the lot-sizing problem from the detailed sequencing and scheduling problem. Our conceptional point of reference is the multi-level capacitated lot-sizing problem (MLCLSP). We show how different streams of research emerged over time. One result is that many practically important problems are still far from being solved in the sense that they could routinely be solved close to optimality in industrial practice. Our review also shows that currently mathematical programing and the use of metaheuristics are particularly popular among researchers in a vivid and flourishing field of research.

Dynamic capacitated lot-sizing problems: a classification and review of solution approaches

In this paper we study the combination of GLSP (General Lot Sizing and Scheduling Problem) and ATSP (Asymmetric Travelling Salesman Problem) approaches with sub-tour elimination and patching to a lot sizing and sequencing problem in the animal nutrition industry. This problem consists of deciding the lots size for each product as well the production sequence of the lots, while meeting demand without backlogs and minimizing production and inventory costs. The coordination of these decisions is a challenge for production scheduling in this industry as the setup times are sequence dependent. The ATSP approaches are compared with relax-and-fix approaches applied to the GLSP (General Lot-sizing and Scheduling Problem) formulated in previous research, using real data from an animal nutrition plant in Sao Paulo state. 
Portuguese: 
Neste artigo estudamos a combinacao de abordagens GLSP (General Lot Sizing and Scheduling Problem) e ATSP (Asymmetric Travelling Salesman Problem) para o problema de dimensionamento e sequenciamento de lotes na industria de nutricao animal. Este problema consiste em determinar o tamanho de cada lote de producao para cada produto, assim como a sequencia de producao destes lotes, de forma a satisfazer a demanda sem atrasos e minimizar os custos de producao e estoques. Uma dificuldade para a programacao da producao nesta industria e integrar estas decisoes, pois os tempos de preparacao da linha de producao sao dependentes da sequencia produtiva e nao obedecem a desigualdade triangular. A abordagem proposta e comparada com abordagens relax-and-fix para o modelo GLSP (General Lot-sizing and Scheduling Problem) estudadas em trabalhos anteriores, utilizando dados reais de um estudo de caso de uma fabrica de nutricao animal localizada no interior de Sao Paulo.

Combinação de abordagens GLSP e ATSP para o problema de dimensionamento e sequenciamento de lotes de produção de suplementos para nutrição animal

This paper breaks new ground by modelling lot sizing and scheduling in a flexible flow line (FFL) simultaneously instead of separately. This problem, called the ‘General Lot sizing and Scheduling Problem in a Flexible Flow Line’ (GLSP-FFL), optimizes the lot sizing and scheduling of multiple products at multiple stages, each stage having multiple machines in parallel. The objective is to satisfy varying demand over a finite planning horizon with minimal inventory, backorder and production setup costs. The problem is complex as any product can be processed on any machine but with different process rates and sequence-dependent setup times & costs. The efficiency of two alternative models is assessed and evaluated using numerical tests.

http://www.jise.ir/article_4044_b674194cc350a8d18a5ba34919e423d5.pdf

Simultaneous Lot Sizing and Scheduling in a Flexible Flow Line

Rolling horizon heuristics for production and setup planning with backlogs and error-prone demand forecasts

Este trabalho trata de um problema pratico de dimensionamento e sequenciamento de lotes em uma fundicao. Existem dois niveis de decisao inter-relacionados: programacao do forno, em que um tipo de liga e escolhido para ser produzido em cada periodo, e planejamento das maquinas de moldagem, que especifica a quantidade de cada item deve ser produzida em cada periodo, isto e, dimensionamento dos lotes. Um modelo de programacao inteira mista e proposto e um metodo de solucao baseado em busca local e desenvolvido. O planejamento da producao e feito usando a tecnica de horizonte rolante, em que somente a programacao para os periodos imediatos e implementada. Os resultados dos testes computacionais sao analisados e comparados com os resultados obtidos utilizando um pacote comercial.

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Alistair Clark

Papers

Combinação de abordagens GLSP e ATSP para o problema de dimensionamento e sequenciamento de lotes de produção de suplementos para nutrição animal

Simultaneous Lot Sizing and Scheduling in a Flexible Flow Line

Rolling horizon heuristics for production and setup planning with backlogs and error-prone demand forecasts

Dimensionamento de lotes e programação do forno numa fundição de pequeno porte

Editorial: Lot sizing and scheduling: Industrial extensions and research opportunities