Over the course of 5 weeks, our group took observations of the service process of the Chuckbox, a tempe restaurant specializing in grilled burgers and chicken. Observations were made on various days and during both Peak and non peak arrival times Here is a summary of our findings, recommendations, and proposed system improvements.
Based on observed data we calculated that capacity in the current systems is limited by the grill. The grill is the subprocess with longest cycle time making it the bottleneck. The calculated cycle time of the grill – 30.7 seconds yielding a capacity of 117.2 customers/hr The there are two components Limiting this process. Grilling labor and the Bun griddle space. One item to note, is the step with the second longest cycle time. This is the cashier at 23.5 seconds. Keep this number in mind as we will revisit this when determining our recommendations.
When observing the normal process flow, we noticed several problems with physical layout. One thing that stood out was the placement of the fountain drink machine. It was located directly in the middle of the line. It took up space, it hindered communication between grill labor and fryer labor. It caused issues when patrons tried to get refills. After numerous visits we saw a clear differentiation in cooking times of the same product. The Chuckbox uses a hardwood grill to cook entrees. The temperature variations can cause these fluctuations in cook times. For example, on one trip, a chicken order took roughly 11 minutes to cook, while at another time, the cooking was completed in 8. The line is restricted by a chain that does not allow a lot of room for patrons to pass one another. Passing is sometimes required because of the differences in cooking times. This is a problem because the hot grill is separated only by glass window which can cause injury.
The overall goal of the process improvement is to increase the capacity of the grill. This can be accomplished by implementing a few changes to the present system. In the system, meat hits the grill and corresponding buns are placed on a griddle. The buns are marked with wooden sticks in various shapes and locations to represent the various entrees that have been ordered. Only 10 buns can be placed on the griddle at a time. In order to increase the capacity of this step we had to find a way to add more griddle space. The obvious choice, move the fountain drink machine. Once removed, this frees up physical space to add a second griddle. It also allows the fry labor to assist on the grill without the limitation of the fountain machine in between. This gets the additional labor required to increase the capacity of the grill. In order to further smooth the system and reduce variability in the system we explored options like adding infrared thermometers to stabilize cooking temperatures and allowing for credit card payments to speed up the checkout process.
The cooking time of the freshly prepared entrees needs to be the bottleneck so that customers are not waiting in line after receiving their food. We looked back at the second highest cycle time in the system. Remember, that was the cashier. We calculated how much we could increase the grill capacity without shifting the bottleneck to the cashier. We found that the maximum capacity at the grill should be 13 entrees. At 14, the bottleneck shifts to the cashier. We did not want to move the bottleneck from the grill.
Based on that analysis, we want to increase the capacity of the grill by 3 entrées. New griddle space combined with shared labor from the fryers, provide this option. This reduces our cycle time to 23.6 seconds. This reduction increases the capacity of the system to 152.4 customer per hour. A study done by Paco Underhill, founder of envirocell, shows customers become disgruntled after a wait time of 3 mins or longer. The new cycle time provided by our improvements reduce the probability that a customer will wait in line longer than 3 mins is reduced from 23% to 4% during peak hours. This leads directly into our next result which is improved customer service. Customers will find shorter wait times, faster times through the system and improved access to the fountain drinks. Once again, improving the experience of the customers will lead to repeat business. Finally, in the improved system, we are able to handle an arrival rate of 123 customers per hour while maintaining the same service level that exists in the current system.
We did not set out to change the atmosphere of the chuckbox. It is the “organized chaos” that gives it the competitive advantage and customer appeal that have made the restaurant a success. Custom orders are the real draw of this establishment. The cooking times of made to order products will ultimately drive the system. Flow time is most critical to achieve customer satisfaction. These recommendations allow us to maintain the core of the system will trimming time from other processes to increase overall capacity. The proposed changes would require capital in the form of a new griddle and thermometers. The relocation of the fountain drink machine would require labor and a relatively small cost. Our recommendation would be for the management to explore the costs of this design modification and begin the financial analysis required to determine the return on investment.
Chuckbox Process Improvement
Analysis and Recommendations for aDysfunctional Business ProcessChris Puckett, Evan Rand, Ritz Rautenbach, Devon Rodgers, Laura Winger
Mean flow time = 420 secondsMean wait time = 275 secondsCapacity = 117.2 customers / hourOrdering Grill Drink Side Order CashierToppingsBarMean Time (sec) 11.8 307.1 17.2 243.6 23.5 60.2St. Deviation (sec) 5.9 71.8 11.5 109.7 10.1 59.7Min. Resources Available 1 10 1 12 1 5Expected Cycle Time (sec) 11.8 30.7 17.2 20.3 23.5 12.0
Fountain Drink placementGrilling temperatures and variabilityCash only policyLimited physical spaceGrill (bottleneck) capacity
Increase grill (bottleneck) capacity1. Move fountain drink to toppings bar2. Add griddle where fountain drink was3. Cross-train fryer to work grill stationBun-sticking codeAdd grill thermometerAdd “plastic” paying options
Grill Capacity vs. Cashier CapacityCalculate the point where “shift” occursNew bottleneck
Increased capacityGrill can serve 3 more customers at a timeReduced wait timesProbability of waiting more than 3 minutesdecreases from 23% to 4% during peak timesImproved customer satisfactionEasier refills, faster process and less waitingAbility to handle faster arrival timesSystem can handle 38% higher than the observed87.8 customers per hour
Have it OUR way!Chris Puckett, Evan Rand, Ritz Rautenbach, Devon Rodgers, Laura WingerNew andImproved