Evaluation of the effect of product demand uncertainty on manufacturing system selection

The use of advanced manufacturing systems is widespread; however, manufacturers frequently face difficult decisions when it comes to selecting the most appropriate system. Uncertainty regarding product demand makes this process more difficult, as many factors are influencing simultaneously. This paper focuses on analyzing the demand uncertainty on the performance of modular drilling manufacturing systems versus other alternatives and evaluating the uncertainty’s impacts on the final decision. To do so, a model is suggested and the effect of demand uncertainty on the output is investigated. Three automotive components of varying complexity are used to examine the approach for making reliable decision

Time and space multi-manned assembly line balancing problem using genetic algorithm

Purpose: Time and Space assembly line balancing problem (TSALBP) is the problem of balancing the line taking the area required by the task and to store the tools into consideration. This area is important to be considered to minimize unplanned traveling distance by the workers and consequently unplanned time waste. Although TSALBP is a realistic problem that express the real-life situation, and it became more practical to consider multi-manned assembly line to get better space utilization, few literatures addressed the problem of time and space in simple assembly line and only one in multi-manned assembly line. In this paper the problem of balancing bi-objective time and space multi-manned assembly line is proposed Design/methodology/approach: Hybrid genetic algorithm under time and space constraints besides assembly line conventional constraints is used to model this problem. The initial population is generated based on conventional assembly line heuristic added to random generations. The objective of this model is to minimize number of workers and number of stations. Findings: The results showed the effectiveness of the proposed model in solving multi-manned time and space assembly line problem. The proposed method gets better results in solving real-life Nissan problem compared to the literature. It is also found that there is a relationship between the variability of task time, maximum task time and cycle time on the solution of the problem. In some problem features it is more appropriate to solve the problem as simple assembly line than multi-manned assembly line. Originality/value: It is the first article to solve the problem of balancing multi-manned assembly line under time and area constraint using genetic algorithm. A relationship between the problem features and the solution is found according to it, the solution method (one sided or multi-manned) is definedPeer Reviewe

Sensitivity analysis for justification of utilising special purpose machine tools in the presence of uncertain parameters

Decision-makers in manufacturing area frequently face machine tool selection problem under uncertainty due to competitive market changes. Special purpose machines (SPMs), a relatively new class of reconfigurable machine tools, are used to react quickly to changes. Justification of utilising these machines vs. other machine tools requires a technique to investigate the sources of uncertainties. In this work, sensitivity analysis is utilised to investigate the sources of these uncertainties and errors which may reveal new insights for evaluating a machine tool. An illustrative example is provided to show the sensitivity of parameters on the economic performance of SPMs compared to the other alternatives. The results show that this analysis provides additional information and moves the decision closer to the optimum alternative

Feasibility analysis of using special purpose machines for drilling-related operations

This work focuses on special purpose machine tools (SPMs), providing a modular platform for performing drilling-related operations. One of the main challenges in using SPMs is selecting the most appropriate machine tool among many alternatives. This thesis introduces a feasibility analysis procedure developed to support decision-making through the assessment of the strengths and limitations of SPMs. To achieve this, technical and economic feasibility analyses, a sensitivity analysis, and an optimisation model were developed and a case study was provided for each analysis. The results indicated that although technical feasibility analysis leads decision-makers to select a feasible machine tool, complementary analyses are required for making an informed decision and improving profitability. Accordingly, a mathematical cost model was developed to perform economic and sensitivity analyses and investigate the profitability of any selected SPM configuration. In addition, an optimisation procedure was applied to the cost model in order to investigate the effect of process parameters and the SPM configuration on the decision-making. Finally, the developed analyses were then integrated into a model in a proper sequence that can evaluate whether the SPM is appropriate for producing the given part and achieving higher productivity. To validate this integrated model three different case studies were presented and results were discussed. The results showed that the developed model is a very useful tool in assisting manufacturers to evaluate the performance of SPMs in comparison with other alternatives considered from different perspectives

Propuesta de mejora para incrementar la productividad en la fabricación de placas expandidas de baterías plomo-ácido a través de balanceo de líneas

Lead-acid batteries are generally used in conventional and electric vehicles, its manufacturing process is characterized by having a long series of routine activities. The purpose of this work is to design a proposal for improvement using line balancing to increase productivity in the production process of expanded plates in this type of batterie. It seeks to equate workloads on workstations, minimize idle time and optimize production time. For this, three great stages were carried out. The first one consisted of characterize the manufacturing process using work study tools; then a literature review about assembly line balancing methods was conducted, and alternative solutions were identified. Finally, a solution method for a SALBP-1 type problem was defined and evaluated. The obtained results showed a reduction in the number of stations that implies improvements in the process, mainly in the productivity of the line and its operators.Las baterías de plomo-ácido son utilizadas generalmente en vehículos convencionales y eléctricos, su proceso de fabricación se caracteriza por tener una larga serie de actividades rutinarias. El presente trabajo tiene como finalidad diseñar una propuesta de mejora utilizando el balanceo de línea con el propósito de incrementar la productividad en la fabricación de placas expandidas en este tipo de baterías, y de esta forma equiparar cargas de trabajo en las estaciones del proceso, minimizando el tiempo ocioso y logrando la optimización del tiempo de producción. Para ello, se llevaron a cabo tres grandes etapas. La primera consistió en la caracterización del proceso de fabricación utilizando herramientas de estudio del trabajo; luego se realizó una revisión de la literatura sobre los métodos de balanceo de líneas de ensamble, y se identificaron las alternativas de solución. Por último, se definió y evaluó un método de solución para un problema del tipo SALBP-1. Los resultados obtenidos mostraron una reducción del número de estaciones generando así, mejoras en el proceso, principalmente en la productividad de la línea y los operarios de esta

A review of cost and profit oriented line design and balancing problems and solution approaches

International audienceThis review paper presents the state of the art on the problems, approaches and analytical models for assembly and transfer line design and balancing that addresses explicitly cost and profit oriented objectives. The discussions aim to facilitate identifying open problems and research areas that have wide practical applications and that necessitate further investigations. Moreover, they might serve as a foundation for developing decision support systems (DSS) that aid managers in planning and designing profitable or cost efficient assembly and transfer lines

作業の自動化難易度と自動化率を考慮した人とロボットのハイブリッド組立ラインの設計法に関する研究

電気通信大学202