Overview
Background:
You have been hired as a consultant to help optimize the checkout operations at a local grocery store. The store management is concerned about long queues and wait times at the checkout counters, which result in customer dissatisfaction and potential revenue loss. Your task is to analyze the store's data and provide recommendations regarding the number of registers and employees needed at the checkout to minimize queues lengths and reduce wait times to less than 3 mins.
Case Study:
The Acme Grocery Store is a medium-sized store with 6 checkout counters. The store is open from 7am to 9pm, 7 days a week. The store manager is concerned about long lines at the checkout registers during the peak hours of 4:00-7:00pm Mon-Fri. Currently three checkout clerks work three registers during this time period. The manager wants to determine the optimal number of registers and employees needed to minimize customer wait times to less than 3 minutes. Data was collected on the arrival rates of customers to the checkout registers from 4:00pm to 7:00pm during the week. Overall arrival rate is said to be poisson distributed. Service time is exponentially distributed with each checkout clerk servicing a mean of 12 customers every hour.
Use the Arrival Time Data in the file Week 4 Case Study Data-2.xlsx Download Week 4 Case Study Data-2.xlsxto determine arrival rate. Use Week 3 Template S2025-1.xlsx Download Week 3 Template S2025-1.xlsxin the Excel Queueing Tool to answer questions below in your simulation model.
Queuing and Simulation Questions:
The following queuing and simulation questions can be used to analyze the Acme Grocery Store checkout process in Excel. Be sure to define the time period used with your answer.
What is the average arrival rate of customers at the checkout registers?
What is the average service rate of the checkout registers?
What is the average wait time for customers with the current three checkout clerks?
What is the optimal number of registers and employees needed to minimize customer wait times of less than 3 mins in the checkout queue?
What is the probability that more than 6 customers are in the system with your proposal?