Scheduling with High Variety of Customized Compound Products

Domestic appliance is an instance of manufacturing various products on clients demand with frequent changes of production. Although the technological process for each individual product is relatively simply, the variety of products, mixed orders, frequent machines changeovers, machines with unusual service policy, lack or limited storage, etc., generates quite nontrivial planning, batching and scheduling problems and furthermore of a huge size. In this paper, we present speci c real process of production of refrigerators, mathematical and graph models of the problem and an outline of solution algorithm, based the on local search approach

Very Fast Non-dominated Sorting

New and very ecient parallel algorithm for the Fast Non-dominated Sorting of Pareto fronts is proposed. By decreasing its computational complexity, the application of the proposed method allows us to increase the speedup of the best up to now Fast and Elitist Multi-objective Genetic Algorithm (NSGA-II) more than two orders of magnitudes. Formal proofs of time complexities of basic as well as improved versions of the procedure are presented. Provided experimental results fully conrm theoretical ndings

Scheduling with high variety of customized compound products

Tyt. z nagłówka.References p. 109-110.Dostępny również w wersji drukowanej.ABSTRACT: Domestic appliance is an instance of manufacturing various products on clients demand with frequent changes of production. Although the technological process for each individual product is relatively simply, the variety of products, mixed orders, frequent machines changeovers, machines with unusual service policy, lack or limited storage, etc., generates quite nontrivial planning, batching and scheduling problems and furthermore of a huge size. In this paper, we present specific real process of production of refrigerators, mathematical and graph models of the problem and an outline of solution algorithm, based the on local search approach. KEYWORDS: scheduling, tabu search

Modelowanie przepływu zadań w elastycznym systemie produkcyjnym z wózkami AGV

Tyt. nagł.ABSTRACT: In this paper the flow shop manufacturing system is considered in which machines are organized into single loop layout and all jobs have to be transported between the machines by a single unidirectional AGV. As a goal function we take the time of completion of all jobs. For the problem the mathematical model and the permutation-graph representation is introduced which are supported by a comprehensive computational example. KEYWORDS: scheduling, flow shop, transport AGV. STRESZCZENIE: W pracy rozważa się system produkcyjny o strukturze przepływowej (szeregowej), w którym maszyny zorganizowane są w układ typu pętla, zaś do transportu zadań pomiędzy maszynami wykorzystuje się pojedynczy, jednokierunkowy wózek AGV. Jako kryterium optymalizacji przyjmuje się moment zakończenia wykonywania zadań procesu technologicznego. Dla problemu przedstawia się model matematyczny oraz wprowadza się model permutacyjno-grafowy, oba poparte wyczerpującym przykładem obliczeniowym. SŁOWA KLUCZOWE: szeregowanie zadań, problem przepływowy, transport AGV

Nowe własności harmonogramów cyklicznych w systemie przepływowym

Tyt. z nagłówka.Bibliogr. s.285.Dostępny również w formie drukowanej.STRESZCZENIE: Praca omawia deterministyczny wariant problemu optymalizacji przebiegu cyklu wytwórczego w przepływowym systemie wytwarzania powtarzalnego z ograniczeniami składowania pomiędzy stanowiskami. Wychodząc od wcześniejszych prac autora dotyczących tego problemu, w niniejszej pracy przedstawiono pewne, także nowe, własności wraz z niepublikowanymi dotychczas dowodami, efektywne algorytmy wyznaczania harmonogramu dla ustalonej kolejności realizacji zadań w cyklu oraz pewne wyniki badań eksperymentalnych. SŁOWA KLUCZOWE: szeregowanie, wytwarzanie cykliczne, algorytm. ABSTRACT: This paper deals with the deterministic variant of the problem of optimization cycle run in flow shop repetitive manufacturing system with no store constraints. Starting from earlier papers of the author on this subject, in this paper there are presented some, also new, properties with unpublished yet proofs, efficient algorithms of finding schedule for fixed order of processing tasks in the cycle as well as some experimental results. KEYWORDS: scheduling, cyclic manufacturing, algorithm

Very fast non-dominated sorting

Tyt. z nagłówka.Bibliogr. s. 22-23.A new and very efficient parallel algorithm for the Fast Non-dominated Sorting of Pareto fronts is proposed. By decreasing its computational complexity, the application of the proposed method allows us to increase the speedup of the best up to now Fast and Elitist Multi-Objective Genetic Algorithm (NSGA-II) more than two orders of magnitude. Formal proofs of time complexities of basic as well as improved versions of the procedure are presented. The provided experimental results fully confirm theoretical findings.Dostępny również w formie drukowanej.KEYWORDS: parallel algorithms, Pareto sorting, computational complexity, GPU computing, multiple-criteria decision analysis, NSGA-II

Problem gniazdowy z transportem i ograniczoną liczbą niededykowanych wózków AGV

Tyt. nagł.ABSTRACT: In this paper the job-shop scheduling problem with transportation is considered. All jobs have to be transported by the finite number of bi-directional automated guided vehicles which are identical and are not assigned to jobs a priori. As goal function we take the completion time of all jobs. For the problem, we propose the algorithm based on tabu search technique. To examine the quality of provided results, computational tests on test instances are performed. KEYWORDS: job-shop, AGV, tabu search. STRESZCZENIE: W pracy rozważa się problem gniazdowy z transportem. Do transportu zadań stosuje się identyczne, dwukierunkowe wózki AGV, których liczba jest ograniczona, zaś przydział do realizacji czynności transportowych nie jest zadany a priori. Jako kryterium optymalizacji przyjmuje się moment zakończenia wykonywania wszystkich zadań. Dla problemu proponuje się algorytm bazujący na technice poszukiwań z zabronieniami. W celu określenia jakości dostarczanych rozwiązań, algorytm poddaje się badaniom numerycznym przy użyciu instancji testowych. SŁOWA KLUCZOWE: problem gniazdowy, AGV, tabu search

Improving the TSAB algorithm through parallel computing

In this paper, a parallel multi-path variant of the well-known TSAB algorithm for the job shop scheduling problem is proposed. Coarse-grained parallelization method is employed, which allows for great scalability of the algorithm with accordance to Gustafon’s law. The resulting P-TSAB algorithm is tested using 162 well-known literature benchmarks. Results indicate that P-TSAB algorithm with a running time of one minute on a modern PC provides solutions comparable to the ones provided by the newest literature approaches to the job shop scheduling problem. Moreover, on average P-TSAB achieves two times smaller percentage relative deviation from the best known solutions than the standard variant of TSAB. The use of parallelization also relieves the user from having to fine-tune the algorithm. The P-TSAB algorithm can thus beused as module in real-life production planning systems or as a local search procedure in other algorithms. It can also provide the upper bound of minimal cycle time for certain problems of cyclic scheduling

Competence-oriented project team planning – university case study

Selection of competent employees is one of the numerous factors that determine the success of a project. The literature describes many approaches that help decision makers to recruit candidates with the required skills. Only a few of them consider the disruptions that can occur during the implementation of a project, such as employee absenteeism and fluctuations in the duration of activities, etc. Collectively, what these approaches amount to is proactive planning of employee teams with redundant competences. Searching for competence frameworks robust to disruptions involves time-consuming calculations, which do not guarantee that an admissible solution will be found. In view of this, in the present study, we propose sufficient conditions, the fulfilment of which guarantees the existence of such a solution. By testing these conditions, one can determine whether there exists an admissible solution, i.e. whether it is at all worth searching for a robust competence framework. The possibilities of practical application of the proposed method are illustrated with an example