Development Of A Decision Support System In Determining Optimum Number Of Server For Nnpc Mega Petroleum Stations
Mbachu, Victor M. , Onyechi, Pius C., Ogunoh, Victor A.
Abstract: Customers queue up at the Nigerian National Petroleum Corporation (NNPC) mega stations to purchase the Premium Motor Spirit (PMS), Dual Purpose Kerosene (DPK) and Automotive Gas Oil (AGO) popularly called petrol, kerosene and diesel respectively in the country. The PMS usually has the highest demand due to its various uses, and the queue for the product at NNPC Mega station during period of scarcity (referred to here as peak periods) has varying average arrival rate at various time of the day. The waiting situation is exasperating to the customers and the management. Thus an operational plan module for determining basically the optimum number of active servers to salve the queue problem in the Stations, while attending to vehicles with minimum demand of 10 litres of PMS was developed. The following optimal active servers were obtained and recommended for the corresponded arrival rate of 1 car per minute to 4 cars per minute, at 72- 80% system utilization rate, a known average service rate of 0.457 cars per minute and average waiting time of 2.6954 minutes to 0.9737 minutes. Simulation of the system was done generating a model which suggests optimum number of server given arrival rates and average service rate.
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