Optimal crew routing for linear repetitive projects using graph theory

The line-of-balance (LOB) technique is considered as an effective tool for planning and scheduling linear repetitive construction projects. One of the main assumptions of the LOB technique is the uniformity and constancy of production rate for an activity. Moreover, some aspects of the LOB technique can be modified in order to suit the nature of construction projects. This paper proposes a hybrid approach for scheduling linear projects that optimizes resource allocation using the LOB scheduling technique. The paper presents an optimization model for resolving resource constraint dilemmas in linear scheduling projects. The proposed model utilizes a Matrix Laboratory (MATLAB) code using graph theory as a searching algorithm to automate the model formulation. The novelty of the model is that it supports decision makers in formulating the optimal crews routing among various activities and also considering the allocation of multitasking skilled crews. A case study for a repetitive 4-km sewage pipeline installation is used to test the capabilities of the proposed model. Results show that the model can feasibly reduce the number of crews employed in linear repetitive construction projects.