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

• Applicant: Professor Dr.-Ing. Willibald A. Günthner
• Subject Area: Structural Engineering, Building Informatics and Construction Operation
• Term: from 2013 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 234929837

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.

• DFG Programme: Research Grants