• Vol. 38 No. 6, 501–507
  • 15 June 2009

Impact of Pharmacy Automation on Patient Waiting Time: An Application of Computer Simulation



Introduction: This paper aims to illustrate the use of computer simulation in evaluating the impact of a prototype automated dispensing system on waiting time in an outpatient pharmacy and its potential as a routine tool in pharmacy management. Materials and Methods: A discrete event simulation model was developed to investigate the impact of a prototype automated dispensing system on operational efficiency and service standards in an outpatient pharmacy. Results: The simulation results suggest that automating the prescription-filing function using a prototype that picks and packs at 20 seconds per item will not assist the pharmacy in achieving the waiting time target of 30 minutes for all patients. Regardless of the state of automation, to meet the waiting time target, 2 additional pharmacists are needed to overcome the process bottleneck at the point of medication dispense. However, if the automated dispensing is the preferred option, the speed of the system needs to be twice as fast as the current configuration to facilitate the reduction of the 95th percentile patient waiting time to below 30 minutes. The faster processing speed will concomitantly allow the pharmacy to reduce the number of pharmacy technicians from 11 to 8. Conclusion: Simulation was found to be a useful and low cost method that allows an otherwise expensive and resource intensive evaluation of new work processes and technology to be completed within a short time.

The growth in the fields of healthcare, pharmaceuticals, life sciences and research in Singapore has increased the demand for and the scope of work of pharmacists. Despite the increase in the number of practicing pharmacists from 770 in 1997 to 1349 in 2007, Singapore still has a comparatively low density of pharmacy personnel of 3 per 10,000 population. In the United Kingdom, there are 5 for every 10,000 population whilst it ranges from 9 to 19 for the United States and Japan.1 A survey of patients in Singapore2 showed that besides prescription accuracy and affordability of medicine, patients expressed preference for waiting time to be less than 30 minutes. As determined from the administrative data of an outpatient pharmacy in Singapore, only about 27% of the patients were served within this target time.

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