Optimization of Direct Transportation Flows for the Removal of Construction Waste Bins with both Resource and Task Availability Interval Constraints

This study focuses on a new real-word problem encountered in the construction sector, which concerns the optimization of the removal of construction waste bins from construction sites to a massification platform, where a limited heterogeneous fleet of tipper trucks (vehicles) must perform direct trips from the platform to the construction sites to collect the waste bins. Each vehicle has a capacity of one bin, it leaves the platform with an empty bin, travels to the construction site, drops off the empty bin in the construction site, collects the full bin and returns to the platform to unload the full bin. The issue is that the vehicles and the construction sites have one or more periods of availability, and thus are not available any time. This problem is modeled as a parallel machine scheduling problem of bin removal tasks on non-identical machines (vehicles), with new constraints that concern the presence of multiple availability intervals for both vehicles and tasks. Two mixed-integer programming (MIP) models are presented and evaluated on 18 new instances derived from real industrial case study.