Multiple Maintenance Activities Research Articles

Single-machine slack due-window assignment scheduling with multiple maintenance activities and position-and-resource-dependent processing times

This paper studies the slack due-window assignment method for single-machine scheduling problems with position-and resource-dependent processing times, for which the actual processing time is a continuous bivariate non-increasing convex function involving position and resource allocation. Only the slack due-window assignment method will be used. Two linear combination problems concerning position-dependent effects and resource allocation will be studied, in which the machine requires multiple maintenance activities. We present the optimal properties or design optimal algorithms to minimise the combination of the makespan, the total completion time and the total absolute deviation of completion time and to minimise the combination of the total costs of tardiness, the slack due date, the earliness cost, and the resource amount. Finally, we also consider the bi-criteria scheduling problem with nonmaintenance activities to minimise the combination of the total resource allocation cost, the weighted number of tardy jobs, and slack due-window assignment costs. A pseudo-polynomial time algorithm is designed to solve the bi-criteria scheduling problem.

Modelling and application of condition-based maintenance for a two-component system with stochastic and economic dependencies

This paper develops a model of a condition-based maintenance policy for a two-component system with both stochastic and economic dependencies. The stochastic dependency is such that the degradation rate of each component depends not only on its own state (degradation level) but also on the state of the other component. The economic dependency is such that combining multiple maintenance activities has lower cost than performing maintenance on components separately. To select a component or components to be preventively maintained, adaptive preventive maintenance and opportunistic maintenance rules are proposed. A cost model is developed to find the optimal values of decision variables. A case study of a gearbox system demonstrates the utility of the proposed model.

Maintenance strategy selection for improving cost-effectiveness of offshore wind systems

This paper proposes approaches to determine the optimal maintenance schedules for offshore wind system such that maintenance cost is minimized. The proposed approaches aim to provide the optimal maintenance schedules for each component using a dynamic approach and for multiple components by proposing an algorithm to optimize grouping multiple maintenance schedules. To increase the accuracy of estimating the maintenance cost in the proposed approaches, a number of impacted parameters such as system reliability, cost–effective, weather condition, maintenance duration, power generation loss during maintenance, market electricity price and offshore wind system location are all considered. Firstly, a dynamic maintenance strategy is proposed to determine an optimal individual maintenance schedule for each component in an offshore wind turbine, in which the failure rate and maintenance cost are critical parameters for the cost model. Then, a grouping maintenance optimization strategy is proposed to determine the grouping maintenance schedule which groups multiple maintenance activities to a grouping maintenance activity. The results indicate that the proposed individual maintenance schedule and grouping maintenance schedule may save an average of 2.33% and 4.56% on maintenance cost over baseline maintenance schedule.

Best Possible Approximation Algorithms for Single Machine Scheduling with Increasing Linear Maintenance Durations

We consider a single machine scheduling problem with multiple maintenance activities, where the maintenance duration function is of the linear form f(t) = a+bt with a ≥ 0 and b > 1. We propose an approximation algorithm named FFD-LS2I with a worst-case bound of 2 for problem. We also show that there is no polynomial time approximation algorithm with a worst-case bound less than 2 for the problem with b ≥ 0 unless P = NP, which implies that the FFD-LS2I algorithm is the best possible algorithm for the case b > 1 and that the FFD-LS algorithm, which is proposed in the literature, is the best possible algorithm for the case b ≤ 1 both from the worst-case bound point of view.

Single-Machine Scheduling with Aging Effects and Optional Maintenance Activity Considerations

This paper explores a single-machine scheduling with aging effects and the problem regarding optional maintenance activity assignment. The jobs’ processing time is assumed to follow a power position-dependent aging model. The optional maintenance activity refers to the situation in which the maintenance activity can be scheduled immediately after processing of any job has been completed except for the last job and the duration of maintenance activity can be of any value from zero to a fixed time interval. A recovery function is proposed to reflect the efficiency of the machine or worker which is improved. The objective of this study is to decide whether and when to implement the maintenance activity into the job sequence, how long the duration of maintenance activity is, and how to schedule so as to minimize the makespan. Once the duration of maintenance activity is known, we introduce an efficient solution for this problem. In addition, when the maintenance activity is completely performed, we showed that the optimal policy is to schedule the maintenance activity in the middle of the task sequence and optimally solved it by lower order algorithm. Finally, we extend the problem to the case of multiple maintenance activities which are completely performed. Hence, the problem is regarded as polynomial time solvable.

Parallel machines scheduling with simultaneous considerations of position-dependent deterioration effects and maintenance activities

This article considers identical parallel-machine scheduling problems with simultaneous considerations of position-dependent deterioration effects and maintenance activities. To counteract the deterioration effects on the machines, we assume that each machine must be maintained exactly once during the planning horizon and the maintenance can be scheduled immediately after completing the processing of any job. We further assume that, after the maintenance on a machine, the machine reverts to its initial condition and the deterioration effect starts anew. The objective is to find jointly the optimal maintenance positions and the optimal job sequences to minimize the total machine load. We provide polynomial time solutions for all the problems studied. Furthermore, we also show that the problem under study remains polynomially solvable when each machine is subject to multiple maintenance activities.

Minimizing the total completion time in single-machine scheduling with aging/deteriorating effects and deteriorating maintenance activities

In a real manufacturing system, a machine may need multiple maintenance activities to improve its production efficiency due to the effects of aging or deteriorating. This paper considers scheduling with aging or deteriorating effects and deteriorating maintenance activities simultaneously on a single machine. We assume that the machine may be subject to several maintenance activities during the planning horizon. However, due to the restriction of budget of maintenance, the upper bound of the maintenance frequency on the machine is assumed to be known in advance. Moreover, we assume that the duration of each maintenance activity depends on the running time of the machine. The objective is to find jointly the optimal maintenance frequencies, the optimal maintenance positions, and the optimal job sequence for minimizing the total completion time. We show that all the problems studied are polynomially solvable.

Estimation of Highway Maintenance Marginal Cost under Multiple Maintenance Activities

This paper focuses on the estimation of highway maintenance marginal costs. Highway maintenance marginal cost has been estimated in the literature using the perpetual overlay indirect approach. This approach assumes that pavement overlay costs dominate maintenance costs and ignores other maintenance activities. This paper focuses on two questions. First, is it acceptable to ignore the less costly activities? Second, if multiple maintenance activities are to be considered, is it acceptable to ignore their interdependence? The results show that less costly maintenance activities cannot be ignored. Furthermore, if multiple activities are to be considered, their interdependence should be taken into account.

Scheduling problems with multiple maintenance activities and non-preemptive jobs on two identical parallel machines

This paper deals with the problem of processing a set of n jobs on two identical parallel machines. In order to reduce the probability of machine breakdown with minor sacrifices in production time, the machines cannot process the jobs consecutively, they need to be maintained regularly (here we assume that the largest consecutive working time for each machine cannot exceed an upper limit T). Two scheduling models are considered. In the first model, the maintenance activities are performed periodically and the objective is to schedule the jobs on two machines such that the makespan is minimized. In the second model, the maintenance activities are determined jointly with the scheduling of jobs, and the objective is to minimize the total completion time of jobs. For the first problem, we introduce an O ( n 2 ) time algorithm named MH FFD and show that the performance ratio of MH FFD is at most max { 1.6 + 1.2 σ , 2 } , where σ ≜ t / T , t is the amount of time to perform each maintenance activity. For the second problem, we apply the classical SPT algorithm to it and show that the worst-case bound of SPT algorithm is no more than 1 + 2 σ . We also point out that for the case of single machine, if the SPT schedule has three batches, then the upper bound of SPT algorithm can be reduced from the known result 21/17 to 11/9 under the assumption that t < T .