Multi-Objective Scheduling Optimisation for Super High-Rise Projects Considering the MRCPSP

Compared with general civil engineering, the horizontal and vertical construction spaces of super high-rise projects intersect more closely within the same time window, which makes the interlocking of resources more likely to cause scheduling confusion. Accordingly, the paper introduces the Multimode Resource Constrained Project Schedule Problem (MRCPSP) model to solve the optimal construction scheduling scheme with the objective of duration-cost-resource balance. In terms of model optimisation, considering the ambiguity of the traditional MRCPSP in defining multi-mode combinations, a definition based on the upper and lower bounds of duration as well as a P-MRCPSP (with Pre-emptive execution) model based on mode optionality for specific processes are proposed. In terms of goal setting, this paper innovatively introduces the resource tension index and realises the resource levelling calculation based on the risk importance of resources. In terms of algorithm optimisation, the NSGA-II algorithm was considered to solve a multi-mode multi-objective model in which the task chain table coding sequence could not satisfy the process logic; the serial scheduling import process was also inefficient, and the elitism strategy high-density solution was easily rejected. The results of the algorithm showed that the minimum duration and cost scheduling solutions were superior to the original solutions, and new patterns were identified for the relationships among the three objective values and for resource scheduling.