Integrating Existing Scheduling Techniques into the Holonic Manufacturing Execution System (Integratie van een productieplanningssysteem met een productie-uitvoeringssysteem gebaseerd op multi-agenttechnologie)
Integrating Existing Scheduling Techniques into the Holonic Manufacturing Execution System
Verstraete, Paul; S0006055
This thesis addresses the relation between manufacturing control and pro duction planning. Manufacturing control has been referred to as the engi ne of production, while detailed production planning steers the producti on. Manufacturing control ensures that basic operations perform as expec ted by management. Production planning allows management to set goals an d to translate these goals to concrete operational objectives. This thes is focuses on planning for day to day operations. Manufacturing companies are often confronted with cha nges, caused either by the client or the supplier. Examples are signific ant fluctuations in customer demand, business opportunities for new type s of production, mergers, lack or abundance of personnel, etc. Manufactu ring industry recognizes the importance of the ability of a company to a dapt to these changes (sometimes also referred to as flexible production ). The thesis proposes a number of software architectura l assets that are part of a product line for the holonic manufacturing e xecution systems developed at PMA K.U.Leuven. This product line facilita tes the development and maintenance of implementations for these holonic manufacturing execution systems. These execution systems predict future behavior and proactively take measures to prevent production problems from occurring. The thesis proposes and evaluates an integrated appro ach for manufacturing control and manufacturing planning. The approach a llows to construct a single system that fulfills both functionalities, w hile allowing for improved support for changes from either client or sup plier side. The system takes into account the output from a plann ing algorithm. It increases the usability of a planning (for instance by including transportation or warehouse management during execution). The system uses the capabilities of a holonic manufac turing execution system to execute the planning. The execution system pr ovides local short term forecasts of the production and responds to unex pected events (such as machine breakdowns). The local short term forecasts make the consequences of the optimisation concrete for the stakeholders involved in the production process. The thesis evaluates this integrated approach in a nu mber of experiments. The experiments show an improved responsiveness of the Holonic Manufacturing Execution Systems towards breakdowns. Both the variation and the average performance suffer less from a breakdown compared to an approach where the HMES only executes the planning or uses no planning at all. This responsiveness is achieved while maintaining a g ood separation of concerns. On the one hand, every planning system can be used unmodified. The HMES adds responsiveness to the functionality the planning system already off ers. On the other hand, the HMES compensates for possible simplification s in the planning system. In the experiments, the planning system ignores transportation and warehous e management and cannot deal with parallel machines with different execu tion times. The holonic manufacturing execution system organizes both tr ansport and warehouse management at run-time. Furthermore, it compensate s for ignoring the different execution times, certainly in the case of a breakdown.