Development of a methodology for agent based schedule optimization in construction considering resource constrained process duration

在这个项目中，引入了一种新的方法，基于离散事件代理，以提高生产力的建设项目。考虑到所有的约束条件，优化的项目进度取决于不同的目标。建筑项目的特点是参与者众多，内部和外部相互依赖。考虑到所有的约束，手动调度达到了它的极限。因此，无论是大的缓冲时间被添加到项目计划或必要的约束条件没有考虑到。一个精确的解决方案，这个NP-难问题的最小化施工完工时间为共同规模的项目进度是几乎不可能在一个合理的时间量-现有的方法通常只考虑单一的片段的优化可能。因此，一个多智能体系统（MAS）创建，这是专门在生成和优化的项目进度计划，由于各自的目标。除了确定最短项目工期目标外，还应将资源部署最小化，以及时完成所有施工任务，并根据资源的特性、数量和使用时间，将资源分配所产生的成本降至最低。过程代理商在中央市场（谈判协议）上征求建议书，所有代理商可以在考虑现有限制的情况下就资源分配进行谈判。根据优化的主题，将可用资源分配给关键流程，并分配相同的资源，以确保理想的施工流程。智能自主代理的应用进一步揭示了项目调度优化的潜力。在现有的启发式方法中，资源在先前任务完成后立即分配，因此不会为潜在的更相关的进程保留。分析了可变资源分配对过程工期和各作业链的影响以及相应的工程后果，施工作业受到各种各样的影响，这些影响是难以预测的，但对项目计划的质量有负面影响。因此，时间表需要迭代的修订，通过整合和重新优化的进度计划的基础上，当前的建设工程。合作和协调的多智能体系统中的各个自治实体允许管理所有的约束和资源分配考虑相关的目标。结果是一种方法，用于在动态多代理框架中应用基于知识的实体来确定优化的施工项目进度，包括相关的约束和资源特定的过程持续时间。

Within this project a new approach based on discrete event agents is introduced to increase productivity of construction projects. Considering all constraints optimized project schedules are generated depending on various objectives.Construction projects are characterized by a huge number of participants and a variety of internal and external interdependencies. Considering all constraints manual scheduling reaches its limits. Hence either large buffer times are added to the project plan or essential constraints are not taken into account.An exact solution to this NP-hard problem of minimizing construction makespan for common sized project schedules is hardly possible within a reasonable amount of time - existing approaches usually consider only single fragments of the optimization possible. Therefore a Multi-Agent-System (MAS) is created, which is specialized in generation and optimization of project schedules due to the respective objectives. Besides the determination of minimum project duration objectives are minimal resource deployment to complete all construction tasks in time as well as minimal costs incurred by resource assignment depending on characteristics, numbers and time of utilization.Process agents request proposals on a central market place (negotiation protocol), where all agents may negotiate on resource allocation whilst considering existing constraints. Depending on the subject of optimization available resources are allocated to critical processes and identical resources are distributed to ensure ideal construction flow.The application of intelligent, autonomous agents reveals further potential for the optimization of project scheduling. In existing heuristic approaches resources are allocated immediately after the completion of prior tasks and will therefore not be reserved for potentially more relevant processes. Moreover the influences of variable resource allocation on process duration and respective operational work chains as well as corresponding consequences on the overall project are analyzed.Construction works are subject to various influences, which are difficult to anticipate but have negative impact on the quality of project plans however. Hence schedules require iterative revision by integrating and re-optimizing the schedule based on the current progress of construction works.Cooperation and coordination of the various autonomous entities in a Multi-Agent-System allows the management of all constraints and the allocation of resources considering relevant objectives. Result is a methodology for the application of knowledge-based entities in a dynamic Multi-Agent-framework to determine optimized construction project schedules comprising relevant constraints and resource specific process durations.