Integrated planning of spare parts and service engineers with partial backlogging

S. Rahimi-Ghahroodi*, A. Al Hanbali, W. H.M. Zijm, J. K.W. van Ommeren, A. Sleptchenko

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


In this paper, we consider the integrated planning of resources in a service maintenance logistics system in which spare parts supply and service engineers deployment are considered simultaneously. The objective is to determine close-to-optimal stock levels as well as the number of service engineers that minimize the total average costs under a maximum total average waiting time constraint. When a failure occurs, a spare part and a service engineer are requested for the repair call. In case of a stock-out at spare parts inventory, the repair call will be satisfied entirely via an emergency channel with a fast replenishment time but at a high cost. However, if the requested spare part is in stock, the backlogging policy is followed for engineers. We model the problem as a queueing network. An exact method and two approximations for the evaluation of a given policy are presented. We exploit evaluation methods in a greedy heuristic procedure to optimize this integrated planning. In a numerical study, we show that for problems with more than five types of spare parts it is preferable to use approximate evaluations as they become significantly faster than exact evaluation. Moreover, approximation errors decrease as problems get larger. Furthermore, we test how the greedy optimization heuristic performs compared to other discrete search algorithms in terms of total costs and computation times. Finally, in a rather large case study, we show that we may incur up to 27% cost savings when using the integrated planning as compared to a separated optimization.

Original languageEnglish
Pages (from-to)711-748
Number of pages38
JournalOR Spectrum
Issue number3
StatePublished - 1 Jul 2017
Externally publishedYes

Bibliographical note

Funding Information:
This publication was made possible by the NPRP award [NPRP 7-308-2-128] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors.

Publisher Copyright:
© 2017, The Author(s).


  • Approximate evaluation
  • Field service
  • Heuristic optimization
  • Maintenance logistics
  • Queueing
  • Spare parts inventory

ASJC Scopus subject areas

  • Management Science and Operations Research


Dive into the research topics of 'Integrated planning of spare parts and service engineers with partial backlogging'. Together they form a unique fingerprint.

Cite this