In all other problems within this course, service rate has been provided for me. I've reviewed the chapter but can't seem to grasp calculation for service rate. It appears from the problem that there are an average of 100 customers arriving per hour (thus the rate of 100 for customers arriving into the system), but when attempting to calculate service rate I'm unsure...I know I must have this rate to complete the problem of wait time in the system, determining the number of servers, etc.
In planning for a major redesign, Beth collected data at her store on several consecutive Saturday mornings. She noticed that customers arrived at the checkout at a rate of approximately 100 per hour. Fully 20 percent of the customers had 10 items or less. Those people took about 2 minutes to serve on average, while customers with more than 10 items took about 4 minutes to process. Beth expects service time to improve when universal price code readers are installed in the new design. Help Beth with her design for the system.
Current Service Rate = 20% of users takes 2 mins + 80% of users takes 4 ...