Combining maintenance activities in an operational Planning Phase: a Set-Partitioning approach

Joint execution of maintenance activities can redua costs becausepreparative activities, like opening a machine, may be shared.Combining execution, however, also implies that activities arecamed out at times other than originally planned. In this paper,we analyse the problem of determining which activities shouldbe combined at which moments in time. We develop a methodologyto represent the cost-effectiveness of combining activities,and to identify an optimal combination plan. The method consistsof three phases: one in which penalty cost functions are derived,another in which combinations are evaluated, and finally onein which the optimal combination is obtained through a set-partitioningalgorithm.     

Evaluation of a new maintenance concept for the preservation of highways

Asphalt roads gradually deteriorate over time and need mendingto remain in a good state. Inspections are performed to obtaininformation about the current state of the road; when the levelof damage reaches the established standards, the road is repairedthrough a maintenance action that is considered most cost-effective.Because of economies of scale, it is to a certain extent economicalto limit the number of maintenance services by integrating neighbouringsegments into a homogeneous section which is completely repaired.In this report we consider the question of whether it is economicallyjustified to adopt a maintenance concept in which the road isoccasionally regenerated from junction to junction with a distanceof several kilometers. The big advantage of junction-to-junctionmaintenance is that it can be done within special road barrierconstructions which reduce the road capacity only slightly,so that the road can be maintained 24 hours a day.