An Application of Queuing Theory to ATM Service Optimization: A Case Study

Unmanaged queues are detrimental to the gainful operation of service systems and results in a lot of other managerial problems. This paper applies queuing theory to determine optimal service level for a case ATM base on a customer-defined criterion of wait time not exceeding eight (8) minutes.  In pursuance of this, the prevailing operation characteristics of the case ATM as a queuing system where defined. Direct non-participatory observation and questionnaire were engaged to record time measurements and primary data. Measurements were taken on arrival times and service times of customers who arrived at the terminal within the hours of 8:00 am to 4:00 pm. The Chi-squared Goodness of Fit test was performed on collected data. This established the interarrival times at the case ATM as exponentially distributed. The M/M/s queuing model therefore best illustrates the ATM queuing system of the case bank. A queuing theory based decision support system was developed as a result and applied to analyse and suggest improvement in waiting time. Two ATMs at a service rate of 0.60 customers per minute is found to be optimal for the case bank albeit waiting time are found to be relatively higher during the hours of 11:00am to 1:00pm and month endings. The research thus reveals that although queuing theory is applicable in finding optimal service levels, waiting time might still be lengthy because of external factors. Service unavailability was observed to be a contributory factor to queue formation at the case ATM. A routine maintenance regime should be actively implemented in curtailing such problems. For short term queue management however, backup-staffs could be engaged during peak periods to handle any additional demand instead of the alternative of installing the rather capital intensive ATM which might be of less utility for most business hours. Queue management should also be made an active part of the bank’s overall strategic queue management processes. Keywords: Queuing Theory, Waiting Time, Service Rate, Arrival Rate, ATM, Optimal Service Leve

Residue Number System-Based Approach to Minimise Energy Consumption in Wireless Sensor Networks

This study harnesses the useful number properties of the residue number system (RNS) to minimise energy consumption in a wireless sensor network. In a traditional cluster-based wireless sensor network, large bit representations of aggregated packets are transmitted to the base station. However, large bit patterns of packets are slower compared to smaller bits. The proposed approach splits aggregated data into a pre-specified number of transmission channels using a moduli set. Cheap energy cost routes from the cluster heads are computed to deliver the chunked aggregated data to the base station. Forward and reverse converters are proposed to encode data into RNS and decode the RNS data that reaches the base station. MATLAB simulation is used to implement the proposed data splitting method and to evaluate network performance. The experimental results suggest that the proposed method is more effective at minimising transmission energy when compared with traditional approaches in which complete packets are transmitted

Queue Management during Health Pandemics: A Queuing Theory Perspective

The era of coronavirus has called for sustained social distancing measures to minimize the spread of the viral disease. Healthcare establishments are reducing the size of their working staff; while others are running their outfits base on shift work in other to ensure protocols for social distancing.  Inherent in social distancing protocol is the potential for generating waiting lines at service delivery points. Healthcare centres in many countries are already inundated with loads of patient’s attendance on daily basis for treatment off mild to severe ailments. COVID-19 has added a further burden on the already frail health systems. Whiles visits are increasing, social distancing measures are to be ensured. Quick service delivery which is an indispensable need of patients visiting hospitals for treatment is shortened. The occurrence of waiting line, an impediment to healthcare provision has become commonplace in most healthcare centres in Ghana in particular. In addition to loss of financial gains, delay and unsatisfactory healthcare could lead to loss of lives. Health units are dealing with the effective management of staff schedules to curtail the impact of COVID-19 and at the same time cover up capacity to meet the added health care delivery demands. Accordingly, efforts to reduce time spent in waiting to receive medical attention is crucial. In this paper we study the queue situation at a case Outpatient Department (OPD) by applying query theory and offer recommendations for queue management. The study was conducted in the month of May 2020. We present also, an approach to determine the optimal number of service windows required to reduce the time spent waiting for healthcare attention. Numerical analysis of the queuing situation at the case department is given also, drawing from relevant equations from queuing theory