Calculate flow rate operations management

AD 605 Operations Management 1. 2. 3. 4. 5. Consider a production process that produces 600 parts per hour. There are 10800 parts in inventory ready to be processed. a. Using Little's Law, calculate the flow time (in hours) for this process. b. A change is made to the production process, and the new flow time is observed to be 10.5 hours. Assuming that the production rate remains 600 parts per hour, what is the new average inventory level? An amusement park serves many customers. During weekends, the park is opened from 10:00 AM to 8:00 PM. The average number of customers is 1800 per day. Each customer buys a ticket from one of eight cashiers, who each take an average of 2.5 minutes to serve a customer. Sixty-five percent of customers go on the roller coaster. This roller coaster serves 24 customers at a time and takes 12 minutes to complete the ride, including getting customers on and off. a. Calculate the effective capacity of the cashiers (customers/hour). b. Calculate the resource utilization of the cashiers. c. Calculate the resource utilization of the roller coaster. Ten workers are present in a painting process for metal parts. Each painter completes one part every 7.5 minutes. During each 8 hour shift, 600 parts are painted. a. Calculate the utilization of the painters. b. Demand has increased to 760 parts per shift. How many painters are needed to have a maximum 95% utilization? Consider a movie theatre complex (i.e., group of theatres), where customers start by waiting in a common line to buy a ticket. Two ticket clerks are employed, and the average service time is 1.5 minutes per customer. Some customers are buying a ticket for a later show and leave the theatre. Other customers wait in a queue for snacks where four servers are employed and the average service time is 2.5 minutes per customer (which includes allowing them into the theatre). The remaining customers wait in a queue to enter the theatre, where one server is available and the service time to confirm their theatre number is 30 seconds per customer. During the peak period of 6 PM to 10 PM, an average of 320 customers arrive at the complex. Currently, the average queue sizes are: 15 customers to buy a ticket, 12 customers to buy snacks, and 4 customers to enter the theatre without snacks. a. On average, what is the flow time (waiting time in minutes) for customers buying a ticket? b. On average, what is the flow time (waiting time in minutes) for customers buying snacks? c. On average, what is the flow time (waiting time in minutes) for customers entering the theatre without buying snacks? A help desk is located at the center of a University’s campus, and serves students with computer problems who arrive at their office. The average waiting time for service is 45 minutes. On a typical day, three helpers serve customers, each spends an average of 12 minutes with the customer they serve. a. What is the average queue size (number of customers)? b. If the service were improved so that the average queue size was 5.0, what would be the average wait time for a customer (in minutes)? AD 605: Operations Management Class 5: Process Flow Measures Fall 2019 Topics ● Process flow measures – flow time, flow rate, inventory ● Little’s Law – flow time estimates – inventory estimates ● Takt time – synchronizing process flow with demand ● Inventory turns measure – relationship between operational measures and financial measures 2 Key Process Flow Measures T = Flow Time (time in process) R = Flow Rate (e.g., units per day) I = Inventory (units in process) also called Cycle Time or Lead Time also called Throughput includes all flow units (e.g., customers, parts, dollars) These measures can be applied to manufacturing or service operations, and they can apply to an operating system or individual processes.