Abstract:
The ATMs have become the most efficient service facility of the banking industry. Therefore,
this study analyzed the performance of such a service system of a state bank in Sri Lanka. The
selected ATM machine was located in front of a university. Thus considerably a longer queue was
observed. The simulation was performed for a single server queuing system using the student
version of Rockwell ARENA 14.5. The aim of the study was to calculate the average waiting time of
the customers, number of customers waiting in queue and number of arrivals and service receipts
in the selected ATM system. Data were collected for one peak hour on two weekdays. The sample
included 100 observations. The inter arrival times and service times were calculated and inserted to
the ARENA input analyzer to find the corresponding probability distributions. The system was run
for a replication length of one hour. The results revealed that the waiting time of customers in
queue and the number waiting were 4.50 minutes and 4.31 respectively. Moreover the performance
of the system was measured by the percentage of customers served in the selected hour. Since the
existing system had less performance rate and higher total waiting time, the study recommended to
locate another ATM machine by assessing the financial feasibility. The results revealed that
customer waiting time can be reduced to 2.20 minutes and number waiting can be reduced to 1.09
by the proposed system. Further the performance of the new system was recorded as 86.67%.
