Multi-objective scheduling for distributed security services

In this paper we deal with a common problem found in the operations of security and preventive/corrective maintenance services: that of routing a number of mobile resources to serve foreseen and unforeseen tasks during a shift. We define the Mobile Re-Allocation Problem (MRAP) as the problem of maximizing the weighted number of tasks on time. For solving the MRAP, we propose to solve successively a multi-objective optimization problem called the stochastic Team Orienteering Problem with Multiple Time Windows (s-TOP-MTW) so as to consider information about foreseen tasks and the arrival process of unforeseen tasks. Solving successively the s-TOP-MTW we find that there is in fact a trade-off between both objectives and that considering the reliability of routes may aid in maximizing the expected proportion of tasks accomplished on time. We also discuss ways of solving larger instances with the genetic algorithm NSGA-II