Evaluating the impact of optimization algorithms for patient transits dispatching using discrete event simulation

N. Furian*, M. O'Sullivan, C. Walker, S. Vössner

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The on-time completion of patient transits can be identified as a bottleneck for the efficiency of health care services in major New Zealand hospitals. Delayed transits of patients between wards and treatment or diagnostic facilities lead to increasing waiting times at clinics and inefficient resource utilization (e.g. surgery teams) as appointment times are not met. Patient transits are carried out by orderlies, but in some cases require the assistance of a nurse. Ad-hoc dispatching of staff members, nurses and orderlies, to transits has been identified as one major source for delays currently observed in the system. To address this issue we present automated, optimized dispatching algorithms for staff members performing those transits. To develop these algorithms, a network formulation of the problem is introduced that is strongly related to classical vehicle routing problem with semi-soft time windows. However, the need to synchronize the routes of staff members of different types (nurses and orderlies) adds a whole new layer of complexity to the problem, as routes cannot be assessed independently. We present a set of algorithms with varying complexity, ranging from simple heuristics to the use of critical path methods to combine mixed integer formulations for the separated orderly and nurse problems. To address a transit service's stochasticity, volatility and the resulting need for constant re-optimization, we embed the optimization algorithms in a discrete event simulation to evaluate their performance under realistic circumstances.

Original languageEnglish
Pages (from-to)134-155
Number of pages22
JournalOperations Research for Health Care
Publication statusPublished - 1 Dec 2018


  • Column generation
  • Discrete event simulation
  • Limited subsequences
  • Meta-heuristics
  • Patient transit
  • Vehicle routing

ASJC Scopus subject areas

  • Surgery
  • Oral Surgery
  • Otorhinolaryngology


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