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Managing flexibility: optimal sizing and scheduling of flexible servers

Author

Listed:
  • Jinsheng Chen

    (Agency for Science, Technology and Research (A*STAR))

  • Jing Dong

    (Columbia University)

Abstract

When managing resource flexibility in service systems, the conventional wisdom is that server flexibility is beneficial due to the resource pooling effect. However, in practice, flexibility often incurs some additional costs, which makes how much flexibility is optimal and how to best utilize the flexible resource a nontrivial question. In this paper, we study the joint staffing and scheduling problem in service systems with two classes of customers and dedicated and flexible servers. The specific feature we consider is that the flexible server may incur a higher staffing cost or a loss of efficiency. We study how flexibility is best utilized in two scenarios: one with deterministic arrival rates and the other with random/uncertain arrival rates. We utilize a heavy-traffic asymptotic framework to develop structural insights. Our results show that the size of the flexible server pool is of a smaller order than the size of the dedicated server pools, and the flexible servers are mostly used to hedge against system stochasticity or demand uncertainty, depending on which source of randomness dominates. The proposed staffing and scheduling policies are easy to implement and achieve near-optimal performance.

Suggested Citation

  • Jinsheng Chen & Jing Dong, 2024. "Managing flexibility: optimal sizing and scheduling of flexible servers," Queueing Systems: Theory and Applications, Springer, vol. 108(3), pages 415-474, December.
    • Handle: RePEc:spr:queues:v:108:y:2024:i:3:d:10.1007_s11134-024-09926-x
    DOI: 10.1007/s11134-024-09926-x
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    References listed on IDEAS

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