http://repository.wyb.ac.lk/handle/1/3062 Fri, 08 May 2026 14:09:20 GMT 2026-05-08T14:09:20Z http://repository.wyb.ac.lk/handle/1/3589 A Method to Minimize Rework Amount Using Mean Particle Diameter: A Case Study of Activated Carbon Manufacturing Preena, TN; Dilanthi, MGS Rework is a major determinant of activated carbon manufacturing industry. This study investigated rework as a case study by determining its severity by identifying its causes. The considered work categories included only the rework of particle size preparation process. The objective of this research was to suggest a method to minimize the rework amount of size category and analyze the root causes for it. The analysis was done mainly over two objects, the crusher machine and particle size distribution process. Feed materials were categorized into two size combinations in the crushing process. The mean particle diameter analysis was done for both. The study found that activated carbon crushing process needed separate gap settings for each size combination. Further, feeding those two size combinations separately, would give more benefits. Further, it would maintain the specified product range at a higher level. Improving the quality of raw materials, checking the size distribution of the materials before feed, adjusting the new gap settings, replacing the rollers after checking attrition, conducting employee awareness programs and systemizing the procedure of issuing bin for feed were suggested as possible solutions along with the feasibility analysis. Thus, the technical team staff, engineers or mechanics can implement suitable programs or methods of gap setting procedures using their knowledge based on these findings. Tue, 01 Jan 2019 00:00:00 GMT http://repository.wyb.ac.lk/handle/1/3589 2019-01-01T00:00:00Z http://repository.wyb.ac.lk/handle/1/3583 Rambandara RDSS Jayasekara, BEGCP; Anuradha, MEN; Silva, MHA; Thanusan, T; Rambandara, RDSS Application of queuing theory in service industry is a common approach of many researchers. More contribution has been done on the application of queuing theory in the field of health care. Delays prevent prompt delivery of health care services which would be disastrous as human life is involved. The study aimed at examining and measuring the performance parameters of a private medical center. It had only one doctor for both checking patients and issuing medicines. The system was observed for a one hour period on three weekdays and a sample was 100 patients. Then the system was modeled using the student version of Rockwell ARENA 14.5. The Input Analyzer recorded the probability distributions for inter arrivals and service rates. The model was run for a replication length of one hour. The results revealed that patient waiting times in queue at the doctor and at the dispensary were 5.03 and 7.32 in minutes respectively. Moreover, the corresponding number of patients waiting at the doctor and dispensary were 4.74 and 7.10. Also, the total waiting time of a patient in the medical center was 31.12 minutes. The percentage of patients served recorded 42.11%. The study recommended to change the resources used in the two processes for increasing the performance. The new model recorded a performance of 62.5 %. Thus authors recommended employing a pharmacist to issue medicine at the dispensary. Consequently, the seating arrangement could be changed allowing maximum number of patients into system. Tue, 01 Jan 2019 00:00:00 GMT http://repository.wyb.ac.lk/handle/1/3583 2019-01-01T00:00:00Z http://repository.wyb.ac.lk/handle/1/3582 Analyzing the University Canteen Performance: A Case Study Rambandara, RDSS; Weerakoon, WMTNK; Dilanthi, MGS The university canteen is a queuing system with time dependent arrival patterns and limited resources. It has created the problem of students waiting in the queue during the lunch hour. This study purposively selected a Sri Lankan state university canteen composed of two counters and corresponding queues. The data were collected during the lunch hour of five consecutive week days. The sample included 200 students. The queuing system was modeled using the student version of Rockwell ARENA 14.5. The inter arrival times were calculated and inserted to the input analyzer to find the corresponding arrival patterns of students to the university canteen queues. It showed non uniform arrival rates explained by different patterns. The modeled system was run for one hour to find average values for waiting time of the students separately in two queues, number waiting in queues and number of arrivals and service receipts. The simulation showed that 64 students received the service among 64 successive arrivals. The results explained the average waiting times in queue 1 and queue 2 to be 2.35 and 3.03 in minutes respectively. The number waiting at counter 1 and 2 were 1.26 and 1.62 customers. The study further revealed the possibility of reducing waiting times at counter 1 and counter 2 to 0.68 and 0.89 minutes respectively by doubling the resources at both counters. The findings suggested improving the customer service of the system by opening an additional counter during the lunch hour and redesigning the layout considering the financial feasibility Tue, 01 Jan 2019 00:00:00 GMT http://repository.wyb.ac.lk/handle/1/3582 2019-01-01T00:00:00Z http://repository.wyb.ac.lk/handle/1/3581 Analysing the Service Performance of a Filling Station: A Case Study Balasooriya, BMAM; Chathurangani, JHD; Nimnadi, TC; Upekha, TDK; Weerakoon, WMTNK Critical decision making is involved as a major problem in different industries including service industry. This paper presented on a Simulation Model for a service organization in the Sri Lankan Context. The objective of the study is to identify the optimized performance practice through simulating the process of a filling station. The observations were taken for inter-arrival times and service times. The sample size was taken as 150 data for a selected time period. The study modeled the system as a single-server queuing system with infinite waiting room size. The data were analyzed using the Student version of Rockwell ARENA 14.5 software. The input analyzer construed Beta and Gamma distributions for inter-arrival times and service times respectively. Moreover, the results showed 4.29 minutes of an average waiting time for a vehicle and approximately number of vehicles in to the queue as 6. The results recommended for another petrol counter with increased service performance in counter 1. The recommended solution was economically feasible. For further improvements, the study suggested a system with two pump counters in one petrol counter, two petrol counters with two pump counters, and changing resources above both recommendations. This study provided numerous opportunities for researchers and managers to optimize problems related to the performance of the system through the best solutions. Tue, 01 Jan 2019 00:00:00 GMT http://repository.wyb.ac.lk/handle/1/3581 2019-01-01T00:00:00Z