| Περίληψη: | Assembly planning methods have been in the centre of industrial and academic research for many decades, since manual assembly costs may often account for even half of the total manufacturing expenses. Existing and emerging manufacturing trends, such as mass customization and personalization, require fast responses when it comes to the conception and realization of the relevant manufacturing systems. Although, work methodologies have been proposed and applied, such as concurrent engineering, gaps still exist between product development and manufacturing. Current Product Lifecycle Management (PLM) systems focus on the coordination of activities among engineers of different disciplines without, however, being capable of providing actual decision support functionality to decision makers. Moreover, solutions for the different phases of assembly planning have been proposed, without however taking into account the holistic nature of assembly planning that spans the different engineering phases.
In this work, a method is proposed to enable the generation of assembly information, relevant to different phases of a product’s lifecycle, from product data available during its design. The approach is accompanied by three applications focusing on assembly planning, assembly execution and End of Life (EoL) product handling. The core method is an algorithm that generates assembly precedence relations between all components of a product. The algorithm uses collision / interference detection as well as constraints and information extraction as the main means to identify the assembly relations. The results of the algorithm are then used in three different applications: End of Life value estimation, Assembly Line Balancing and Simulation and Assembly Instructions Generation. The applications target both engineers that work in overlapping phases of product and production development as well as the manual assembly operators during execution of the actual processes.
The Assembly Precedence Diagram Generation (APDG) algorithm was developed as an add-on to a widely-used CAD software. The developed application has a minimum input requirement which concerns the selection of the base part(s) as well as configuring the algorithm’s performance through different options. The performance of the algorithm has been tested by data provided by the automotive industry. The rest of the applications were developed using three different approaches. More specifically, the applications relevant to assembly line planning were developed as part of a collaborative web-platform that can also extract and use information residing in engineering files. The assembly instruction generation and visualisation was developed as a separate module and an EoL indicators calculator was developed as a macro application. The development of the applications relevant to assembly line planning involved the elaboration of a new method integrating Discrete Event Simulation (DES) with Assembly Line Balancing (ALB). All proposed applications have been tested on the basis of industrial data and the respective results are provided using time and cost related indicators. The results highlight the benefits of applying the developed methods in industrial environments. More specifically, the effectiveness of the APDG in generating assembly information for use in both production planning and EoL evaluation of products is presented, as well as the added value of the proposed integrated approach (assembly line balancing and simulation) during production design.
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