Comparative study of heuristics algorithms in solving flexible job shop scheduling problem with condition based maintenance

Purpose: This paper focuses on a classic optimization problem in operations research, the flexible job shop scheduling problem (FJSP), to discuss the method to deal with uncertainty in a manufacturing system. Design/methodology/approach: In this paper, condition based maintenance (CBM), a kind of preventive maintenance, is suggested to reduce unavailability of machines. Different to the simultaneous scheduling algorithm (SSA) used in the previous article (Neale & Cameron,1979), an inserting algorithm (IA) is applied, in which firstly a pre-schedule is obtained through heuristic algorithm and then maintenance tasks are inserted into the pre-schedule scheme. Findings: It is encouraging that a new better solution for an instance in benchmark of FJSP is obtained in this research. Moreover, factually SSA used in literature for solving normal FJSPPM (FJSP with PM) is not suitable for the dynamic FJSPPM. Through application in the benchmark of normal FJSPPM, it is found that although IA obtains inferior results compared to SSA used in literature, it performs much better in executing speed. Originality/value: Different to traditional scheduling of FJSP, uncertainty of machines is taken into account, which increases the complexity of the problem. An inserting algorithm (IA) is proposed to solve the dynamic scheduling problem. It is stated that the quality of the final result depends much on the quality of the pre-schedule obtained during the procedure of solving a normal FJSP. In order to find the best solution of FJSP, a comparative study of three heuristics is carried out, the integrated GA, ACO and ABC. In the comparative study, we find that GA performs best in the three heuristic algorithms. Meanwhile, a new better solution for an instance in benchmark of FJSP is obtained in this research.Peer Reviewe

Évaluation de l'efficacité du processus de formation au sein de l’entreprise SONATRACH -HBK- Ouargla (2013-2016)

The aim of this study is to trace the training process of the oil company Sonatrach Direction HBK, as well as the evaluation of its effectiveness. A finding of HR was made according to three indicators;  (Indicator of workforce status by socio-occupational category and their distributions - indicator of the workforce status by division and gender distribution indicator), subsequently other indicators are used to evaluate and analyse the performance of this process, such as (the indicator of the number of training operations carried out, the evaluation indicator of the actual and projected training plans and the cost of training indicator). The analytical descriptive method was used for the analysis of the data of the company, some concern that the year 2016, and others spread over the period from 2013 to 2016. The study concluded the existence of a lack of efficiency of the training process due to the perceived difference in the actual and projected results of the training; however, the company attaches great importance to the training of its employees in all its categories attested in the number indicator of training operations carried out.L’objectif de cette étude est de tracer le processus de formation de l’entreprise pétrolière Sonatrach Direction HBK, ainsi que l’évaluation de son efficacité. Un constat des RH a été fait selon trois indicateurs ; (Indicateur  de situation d’effectifs par catégorie socioprofessionnelle et leurs répartitions- indicateur de la situation d’effectifs par division et indicateur  de répartition par genre), par la suite d’autres indicateurs interviennent pour évaluer et analyser la performance de ce processus tel que (l’indicateur du nombre d’opérations de formation effectué, l’indicateur d’évaluation des plans  prévisionnels et réels de la formation et l’indicateur du coût de la formation). La méthode descriptive analytique a été utilisée pour l’analyse des données de l’entreprise, certaines concernent que l’année 2016, d’autres s’étale sur la période de 2013 à 2016. L’étude a conclu l’existence d’un manque d’efficacité du processus de formation dû à l’écart perçu dans les résultats prévisionnels et réels de la formation, cependant l’entreprise accorde une grande importance à la formation de ses employés dans toutes ses catégories attestées dans l’indicateur du nombre d’opérations de formation effectuées.&nbsp

الأنماط القيادية لمدراء المدارس الابتدائية و أثرها على الدافعية للإنجاز لدى المعلمين. – دراسة ميدانية في المدارس الابتدائية ولاية الوادي–

تناولت هذه الدراسة موضوع: الأنماط القيادية لمدراء المدارس الابتدائية وأثرها على الدافعية للإنجاز لدى المعلمين، وتهدف إلى ما يلي: - التعرف على الأنماط القيادية السائدة في إدارة مدارسنا الابتدائية. - التعرف على مستوى الدافعية للإنجاز لدى معلمي المدارس الابتدائية والوقوف على واقعها في مدارسنا. - الكشف عن مدى أثر النمط القيادي لمدير المدرسة الابتدائية في الدافعية للإنجاز لدى المعلمين. تقدم الدراسة الفرضيات التالية: - توجد فروق ذات دلالة إحصائية في مستوى الدافعية للإنجاز لدى المعلمين الذين يعملون تحت إدارة مدير ديكتاتوري والمعلمين الذين يعملون تحت إدارة مدير ديمقراطي. - لا توجد فروق ذات دلالة إحصائية في مستوى الدافعية للإنجاز حسب الجنس لدى المعلمين الذين يعملون تحت قيادة مدير ديمقراطي. - لا توجد فروق ذات دلالة إحصائية في مستوى الدافعية للإنجاز حسب الجنس لدى المعلمين الذين يعملون تحت قيادة مدير ديكتاتوري. - لا توجد فروق ذات دلالة إحصائية في مستوى الدافعية للإنجاز لدى المعلمين حسب الجنس. و يتم ذلك باستخدام استبيان تحديد الأنماط القيادية لمديري المدارس الابتدائية من وجهة نظر المعلمين ، و استبيان قياس مستوى الدافعية للإنجاز لدى المعلمين، ثم تحليل النتائج إحصائيا باستخدام اختبار(ت) لدلالة الفروق بين عينتين منفصلتين باستخدام برنامج الإحصاء في العلوم الاجتماعية spss . أجريت هذه الدراسة على عينة مكونة من 268 معلما ومعلمة من 87 مدرسة ابتدائية من مناطق ريفية وحضرية من ولاية الواد

Optimisation des plannings des affectations multi niveaux des flux des céréales importées

International audienceDans cet article on s'intéresse aux problèmes de prise de décision dans le domaine de la distribution des céréales en Tunisie notamment ceux relatifs à la planification et à l'affectation multi niveaux des céréales importés. L'objectif est d'optimiser la gestion d'une entité de la chaîne logistique céréalière depuis l'approvisionnement (importation) jusqu'à la vente aux clients (minoteries, semouleries,...) en passant par trois niveaux d'affectation. A cet effet on a développé une approche de résolution basée sur la décomposition du problème en deux sous problèmes complémentaires et on a adopté le principe du chaînage arrière (flux tiré). Cette démarche a permis de réduire la complexité et la taille du problème global sans pour autant mettre en cause la qualité de la solution recherchée. Ainsi, la formulation mathématique des deux sous problèmes a permis de dégagé les fonctions à optimiser et les contraintes à respecter. Devant le dilemme du choix d'une méthode de résolution, on s'est orienté vers l'adaptation d'une méthode exacte, notamment l'algorithme de Simplex auquel on a apporté une extension afin de relaxer les contraintes non linéaires. Enfin, les résultats numériques fournis par cette approche ont montré que cette dernière engendre des économies pouvant atteindre jusqu'à 20% sur les coûts alloués au transport des céréale

Comparative study of heuristics algorithms in solving flexible job shop scheduling problem with condition based maintenance

Purpose: This paper focuses on a classic optimization problem in operations research, the flexible job shop scheduling problem (FJSP), to discuss the method to deal with uncertainty in a manufacturing system. Design/methodology/approach: In this paper, condition based maintenance (CBM), a kind of preventive maintenance, is suggested to reduce unavailability of machines. Different to the simultaneous scheduling algorithm (SSA) used in the previous article (Neale & Cameron,1979), an inserting algorithm (IA) is applied, in which firstly a pre-schedule is obtained through heuristic algorithm and then maintenance tasks are inserted into the pre-schedule scheme. Findings: It is encouraging that a new better solution for an instance in benchmark of FJSP is obtained in this research. Moreover, factually SSA used in literature for solving normal FJSPPM (FJSP with PM) is not suitable for the dynamic FJSPPM. Through application in the benchmark of normal FJSPPM, it is found that although IA obtains inferior results compared to SSA used in literature, it performs much better in executing speed. Originality/value: Different to traditional scheduling of FJSP, uncertainty of machines is taken into account, which increases the complexity of the problem. An inserting algorithm (IA) is proposed to solve the dynamic scheduling problem. It is stated that the quality of the final result depends much on the quality of the pre-schedule obtained during the procedure of solving a normal FJSP. In order to find the best solution of FJSP, a comparative study of three heuristics is carried out, the integrated GA, ACO and ABC. In the comparative study, we find that GA performs best in the three heuristic algorithms. Meanwhile, a new better solution for an instance in benchmark of FJSP is obtained in this research.Peer Reviewe

Application of Postponement Strategy in Distribution Period for Treating Uncertain Demand in Supply Chain Management

International audienceUncertain demand is one of the most important uncertainties in supply chain management. Different from the traditional methods, such as dynamic inventory control, estimation of demand, we propose to apply postponement strategy to treat uncertain demand in the process of distribution in supply chain. Postponement has been appreciated in recent decades, mainly in manufacturing period of realizing mass customization and decoupled system. With postponement strategy, we could address demand with very different quantity. Based on assumption of ideal cooperation among all the enterprises in the same supply chain, a linear programming model is generated, with bi-objective of minimizing the inherent costs of goods and transportation cost. Through tested in an example numeric, it is demonstrated feasible to reschedule supply chain regardless of quantity of demand and to supply different replenishment strategy for decision maker

Comparative study of heuristics algorithms in solving flexible job shop scheduling problem with condition based maintenance

Purpose: This paper focuses on a classic optimization problem in operations research, the flexible job shop scheduling problem (FJSP), to discuss the method to deal with uncertainty in a manufacturing system. Design/methodology/approach: In this paper, condition based maintenance (CBM), a kind of preventive maintenance, is suggested to reduce unavailability of machines. Different to the simultaneous scheduling algorithm (SSA) used in the previous article (Neale & Cameron,1979), an inserting algorithm (IA) is applied, in which firstly a pre-schedule is obtained through heuristic algorithm and then maintenance tasks are inserted into the pre-schedule scheme. Findings: It is encouraging that a new better solution for an instance in benchmark of FJSP is obtained in this research. Moreover, factually SSA used in literature for solving normal FJSPPM (FJSP with PM) is not suitable for the dynamic FJSPPM. Through application in the benchmark of normal FJSPPM, it is found that although IA obtains inferior results compared to SSA used in literature, it performs much better in executing speed. Originality/value: Different to traditional scheduling of FJSP, uncertainty of machines is taken into account, which increases the complexity of the problem. An inserting algorithm (IA) is proposed to solve the dynamic scheduling problem. It is stated that the quality of the final result depends much on the quality of the pre-schedule obtained during the procedure of solving a normal FJSP. In order to find the best solution of FJSP, a comparative study of three heuristics is carried out, the integrated GA, ACO and ABC. In the comparative study, we find that GA performs best in the three heuristic algorithms. Meanwhile, a new better solution for an instance in benchmark of FJSP is obtained in this research