Journal of Medical Systems

, Volume 36, Issue 2, pp 707–713 | Cite as

Analysis of Factors Causing Long Patient Waiting Time and Clinic Overtime in Outpatient Clinics

  • Zhecheng ZhuEmail author
  • Bee Hoon Heng
  • Kiok Liang Teow
Original Paper


This paper is focused on the factors causing long patient waiting time/clinic overtime in outpatient clinics and how to mitigate them using discrete event simulation. A two-week period of data collection is conducted in an outpatient clinic of a Singapore government hospital. Detailed time study from patient arrival to patient departure is conducted, and the possible factors causing long patient waiting time/clinic overtime are discussed. A discrete simulation model is constructed to illustrate how to improve the clinic performance by mitigating the detected factors. Simulation and implementation results show that significant improvement is achieved if the factors are well addressed.


Outpatient clinic Appointment scheduling Consultation waiting time Clinic overtime Discrete event simulation 



The authors wish to sincerely thank staffs in the Singapore government hospital for providing source data used in this study and professional opinions.


  1. 1.
  2. 2. [24 March 2010].
  3. 3.
  4. 4.
    Bailey, N., A study of queues and appointment systems in hospital outpatient departments, with special reference to waiting-times. J R Stat Soc Ser 14:185–189, 1952.Google Scholar
  5. 5.
    Welch, J. D., and Bailey, N., Appointment systems in hospital outpatient departments. The Lancet 259:1105–1108, 1952.CrossRefGoogle Scholar
  6. 6.
    Welch, J. D., Appointment systems in hospital outpatient departments. Oper Res Quart 15(3):224–237, 1964.CrossRefGoogle Scholar
  7. 7.
    Soriano, A., Comparison of two scheduling systems. Oper Res 14:388–397, 1966.MathSciNetCrossRefGoogle Scholar
  8. 8.
    Liu, L., and Liu, X., Block appointment systems for outpatient clinics with multiple doctors. J Oper Res Soc 49(12):1254–1259, 1998.zbMATHGoogle Scholar
  9. 9.
    Vanden Bosch, P. M., Dietz, C. D., and Sumeoni, J. R., Scheduling customer arrivals to a stochastic service system. Nav Res Logist 46:549–559, 1999.zbMATHCrossRefGoogle Scholar
  10. 10.
    Lau, H., and Lau, A. H., A fast procedure for computing the total system cost of an appointment schedule for medical and kindred facilities. IIE Trans 32(9):833–839, 2000.Google Scholar
  11. 11.
    Ho, C., and Lau, H., Minimizing total cost in scheduling outpatient appointments. Manage. Sci. 38(12):1750–1764, 1992.zbMATHCrossRefGoogle Scholar
  12. 12.
    Wang, P. P., Static and dynamic scheduling of customer arrivals to a single-server system. Nav. Res. Logist. 40:345–360, 1993.zbMATHCrossRefGoogle Scholar
  13. 13.
    Cayirli, T., and Veral, E., Outpatient scheduling in health care: a review of literature. Prod. Oper. Manage. Soc. 12(4):519–549, 2003.CrossRefGoogle Scholar
  14. 14.
    Ho, C., and Lau, H., Evaluating the impact of operating conditions on the performance of appointment scheduling rules in service systems. Eur. J. Oper. Res. 112:542–553, 1999.zbMATHCrossRefGoogle Scholar
  15. 15.
    Aharonson-Daniel, L., Paul, R. J., and Hedley, A. J., Management of queues in out-patient departments: the use of computer simulation. J. Manage. Med. 10(6):50–58, 1996.CrossRefGoogle Scholar
  16. 16.
    Clague, J. E., Reed, P. G., Barlow, J., Rada, R., Clarke, M., and Edwards, R. H. T., Improving outpatient clinic efficiency using computer simulation. Int J Health Care Qual Assur 10(5):197–201, 1997.CrossRefGoogle Scholar
  17. 17.
    Harper, P. R., and Gamlin, H. M., Reduced outpatient waiting times with improved appointment scheduling: a simulation modelling approach. OR Spectrum 25(2):207–222, 2003.zbMATHCrossRefGoogle Scholar
  18. 18.
    Fetter, R., and Thompson, J., Patients’ waiting time and doctors’ idle time in the outpatient setting. Health Services Res. 1:66–90, 1966.Google Scholar
  19. 19.
    Klassen, K. J., and Rohleder, T. R., Scheduling outpatient appointments in a dynamic environment. J. Oper. Manag. 14(2):83–101, 1996.CrossRefGoogle Scholar
  20. 20. [24 March 2010].

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Zhecheng Zhu
    • 1
    Email author
  • Bee Hoon Heng
    • 1
  • Kiok Liang Teow
    • 1
  1. 1.National Healthcare GroupSingaporeSingapore

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