Scheduling Simultaneous Resources: A Case Study on a Calibration Laboratory.

A calibration laboratory studied in this research performs a thermal test that requires an analyst for setup and processing and an oven to perform such an essay. For convenience, it’s possible to group some of the essays according to the oven capacity. In this scenario, this paper proposes a scheduling approach to minimize the total flowtime of the orders. This is a multiple resource scheduling problem, where a resource (operator) is used on two processes (oven setup and analysis). In contrast to the classical definition of multiple resource scheduling problems, the oven setup process requires the presence of the operator only for the startup of the process. To solve this problem, we derived: (i) a mixed-integer formulation; (ii) an Ant Colony Optimization (ACO) approach. On those developments, we also discuss some structural properties of this problem, that may lead to further advances in this field in the future. Our results show the ACO approach as a good alternative to the MIP, especially when solving instances with 30 service orders.