Global Journal of Researches in Engineering, J: General Engineering, Volume 22 Issue 1

Improving Trucks Management at Dumpsites through the Application of Queue Theory- The Case of Solous III Dumpsite, Igando, Lagos State Christopher Gbenga α Akande σ Abstract- Queue models are potent and veritable tools for urgent allocation of resources and basis for planning officers, resource managers and corporate organizations to respond to the demand rate with appropriate service rate. The usefulness of queue model in developing relevant policies for allocating and managing resources at the dumpsites has been emphasized in this study. Some factors (number of trucks and average waiting time in the system and in the queue etc.) were used to measure the performance of Solous III dumpsite based on the trucks’ arrival rate and corresponding service rate rendered by the managers of this dumpsite. This study used simple queue model (M/M/1) of First Come, First Served (FCFS) to evaluate trucks activities at the dumpsite. The performance measures include: numbers of trucks in the queue and in the system, waiting time of trucks in the queue and in the system as well as the probabilities associated with the trucks at the dumpsite. The queue analysis indicated that the traffic intensity was 0.96 which is close to 1 and that an average of 24 trucks are in the system while an average of 23 trucks are in the queue per hour. Average waiting time in the queue and in the system accounted for 28mins and 30mins respectively. The study’s results also showed 96% probability that a truck will queue on arrival before being served while the probability that a truck will not queue on arrival is just 4%. The result of the study was validated through the use of Chi-square test. The outcome of the test was not significant as P-value was less than the critical value. It was observed based on the findings of the study that the problem of long queue will persist if no drastic measure is put in place by the dumpsite’s managers. Hence, the study recommended that another service channel be created to enhance the service rate; creation of slip roads of at least 500 meters on both sides of the major road to serve as waiting area for the trucks to reduce traffic congestion at the dumpsite’s area and consequently improve the level of trucks’ turn-around from the dumpsite. Keywords: queue, queue models, performance measures, trucks, dumpsites etc. I. I ntroduction he need for orderliness in most human activities that could result in chaos informed the art and science of queuing. Precious hours and resources are always lost to chaotic situations that occur in our everyday life. Queues are waiting lines which are Author α : School of Transport, Lagos State University Author σ : Ojo, Lagos State, Nigeria. e-mail: akandechristo@gmail.com common experiences at public places such as hospitals’ drug dispensaries (Green, 2003), hospitals’ General Out-Patient Department (GOPD) (Ameh, et al 2013), Bus Stops (Koko, 2018), Bus Stations, Port Terminals (Oyatoye, et al), Petrol Filling Stations (Akinnuli, 2014), Banks and ATM points (Famule, 2010), Shopping Malls (Hall, 1990), Arrival and Departure Rooms of Airports, Eateries (Onoja, et al, 2018) to mention but a few. Queues also occur in service industries – when jobs have to wait for machine process or at telecommunication centres when calls are on hold until they are mature (Sharma, 2004) and vehicles have to wait until Traffic Signal Lights (TSL) turn green at road intersections (Anokye, et al 2013), among others. At Dumpsites, trucks have to wait in-lines to get served due to limited service facilities to prevent unnecessary traffic congestion. Queue theory is an important tool used to model many supply chain problems and it is mostly applicable to situations where customers form a line and wait to be served by the service facility (Odior, 2013). A queue generally can be formed by vehicles, jobs or humans especially when the rate of arrival of items exceeds that of service required (Paul and Akpofire, 2015). Where arriving customers are being attended to by a single server, the queue system is said to be a simple or single queue system. If it is two or more, the queue system is referred to as multiple or multi-servers system (Saaty, 1983). At any point a customer arrives and the server is busy, the customer has to join a queue to be served. The rate at which customers arrive for service is known as arrival rate per unit of time (Taylor, 1994), while the average number of completed service per unit of time is known as service rate. The service rate depends on the service system adopted by the organization’s management (single or multiple) and the service discipline which could be First Come, First Served or Last Come, First Out (Tanner, 1995). There is the probability that arriving customer at a service point has to wait for some moment before being attended to especially if on arrival, it finds one or more customers already at the service point. This process is otherwise T lobal Journal of Researches in Engineering ( ) Volume XxXII Issue I Version I J G 31 Year 2022 © 2022 Global Journals & .