IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________________ Volume: 06 Issue: 10 | Oct-2017, Available @ http://www.ijret.org 30 A STUDY OF SERVICE WAIT TIMEAND ITS IMPROVEMENT IN ACAFETERIA USING DISCRETE EVENT SIMULATION Sriram Velumani 1 , Suganda Pitchiah 2 , He Tang 3 1 School of Engineering Technology, Eastern Michigan University, USA 2 School of Engineering Technology, Eastern Michigan University, USA 3 School of Engineering Technology, Eastern Michigan University, USA Abstract Service wait time is a key performance indicator in the food service industry. A real-case scenario of a cafeteria situated on a college campus is studied for service time. During the lunch hours, there is always a large queue that impacts serviceability. This study identifies the stations and events where the wait time increase and suggests with a solution. A discrete event simulation (DES) model is developed with the information and factors gathered based on observation. The simulation model suggests the places and time periods where the service bottle neck occurs, shows the queues dispersion, and helps in coming up with cost effective solution. Three instants have been simulated for reducing wait time without affecting serviceability: addition of resources, stations which facilitate easy dispersion, and effective planning on the preparation charts. The supply and demand information for an influx is also studied to help optimize planning the cafeteria operations. Keywords: Discrete event simulation, service time, bottleneck, queue. ---------------------------------------------------------------------***-------------------------------------------------------------------- 1. INTRODUCTION A cafeteria is a type of food service where there normally is little waiting staff for table services. As cafeterias require few employees, they are often found within a larger institution, catering to the clientele of the institution. Cafeteria customers are either charged a flat rate for admission (as in a buffet) or pay at the check-out for the item selected. 1.1 Literature Review Several important factors like taste, cleanliness, restaurant layout, and settings determine the popularity of a restaurant. These factors, when well managed, are able to attract a plenty of customers. However, a factor needs to be considered especially when a restaurant has already succeeded in attracting customers. This factor is the customers queuing or wait time [1].Customers may view wait time negatively as a result customers may leave the line or not return [2]. Wait time also affects serviceability and customer satisfaction, Lee and Lambert [3] used a simulation model to identify whether wait time could be managed effectively to improve customer satisfaction in a cafeteria. They concluded that a simulation model is an effective tool to evaluate the levels of wait time for each service station, to examine average wait time, and to estimate the impact of operational changes. They further argued that understanding the relationships between wait time, satisfaction, and service quality is a strong foundation for effective wait time management. Several studies have been done on the queue theory. Researchers have used queuing theory to model the restaurant operations, to reduce cycle time, as well as to increase throughput and efficiency [4]. They used both analytical and simulation to model, study, and validate queue. Mathias and Erwin [5] built a model of real-case scenario of a restaurant using an analytical method and validated the data using Little’s theorem to show queue theory satisfies the model when tested with a real-case scenario. The Little’s theorem [6] describes the relationship between throughput rate (i.e. arrival and service rate), cycle time, and work in process (i.e. number of customers/jobs in the system). This relationship has been shown to be valid for a wide class of queuing models and estimate the performance change when the system is modified [7]. Several simulation tools are used for building restaurant models like Quick Service Restaurant Simulation (QSRS)module [8], Restaurant Modeling Studio (RMS) [9], and discrete event simulation (DES), such as Monte Carlo Simulation[10]. Discrete-event system simulation is the modeling of systems in which the state variable changes only at a discrete set of points in time. The simulation models are analyzed by numerical methods. The main advantage of using DES techniques is that an analysis can be performed to indicate where the processes are being delayed and “what if” questions can be answered, particularly for a new system proposal[11]. Chou and Liu [12] built a DES model to reduce the wait time in a fast-food restaurant. They concluded that no significant evidence indicates that a one line queuing system is better than multi-line queuing system. During the busiest hours the customer wait time increases dramatically, the