Minimizing the cost of maintenance activities involving flow-time and tardiness penalties with unequal release dates and set-up times
Abstract
This paper proposes important results relating to minimizing the sum (or a convex combination) of tasks’ flow-time and tardiness with unequal release dates and set-up times. Firstly, a locally optimal priority rule (FTRS, FTRWS) is proposed for minimizing the sum of a convex combination of the task’s flow-time and tardiness. This local optimality rule is used in an off-line scheduling algorithm with a complexity of O(n3) on a set of n tasks. Using this algorithm combined with the tasks urgency criterion in a maintenance process, we developed an on-line algorithm for tasks scheduling with q task repairers in parallel. This latter algorithm is finally used to schedule and assign preventive maintenance tasks to a distributed system's repairers. As shown in appropriate numerical simulations, its efficiency enables to minimize the cost of preventive maintenance tasks, expressed as the sum (or a convex combination) of the tasks’ tardiness and flow-time.