# Flowchart and Theoretical Flow Time

Recall the evanstonian, an upscale independent hotel that caters to both bussines and leisure travelers, introduced in chapter 3 in exercise 3.10. when a guest calls room service at the evanstonian, the room-service manager takes down the order. She then submits an order ticket to the kitchen to begin preparing the food. She also gives an order to the sommelier (i.e., the wine waiter) to fetch wine from the cellar and to prepare any other alcoholic beverages. Eighty percent of room-service orders include wine or some other alcoholic beverage. Finally, she assigns the order to one of six waiters. Orders may be placed in a buffer if resource (i.e., a waiter, a sommelier, or the kitchen) is not immediately available. Taking down the order and assigning work to the kitchen, sommelier, and waiter on average takes 4 minutes. It takes the kitchen 18 minutes to prepare the typical order. There is a single sommelier. He fetches and readies the wine while the kitchen is preparing the meat. The sommelier takes 6 minutes to prepare and order. While the kitchen and the sommelier are doing their task, the waiter readies a cart (i.e., puts a tablecloth on the cart and gathers silverware). The waiter is also responsible for nonalcoholic drinks. In total, it takes the waiter 10 minutes to prepare the average order. Once the food, wine, and cart are ready, the waiter delivers it to the guest´s room. If the waiter is not immediately available to deliver the order, the food, wine, and cart are held in buffers until he is. It takes the waiter on average 12 minutes to deliver the meal and return to the room –service station. At the room-service station, the waiter debits the guest´s account. This takes 2 minutes. The waiter may wait to do the billing if he another order to prepare or deliver. a) Draw a process map for the room-service process.

b) What is the theoretical flow time of the process?

c) The average flow time of the process was measured to be 60 minutes. What is the flow time efficiency? 4.2

Kristen and her roommate are in the business of baking custom cookies. As soon as she receives an order by phone, Kristen washes the bowl and mixes dough according to the customer´s order- activities that take a total of 6 minutes. She then spoons the dough onto a tray that holds one dozen cookies (2 minutes). Her roommate then takes 1 minute to set the oven and place the tray in it. Cookies are baked in the oven for 9 minutes and allowed to cool outside for 5 minutes. The roommate then boxes the cookies (2 minutes) and collects payment from the customer (1 minute). a) Drow a flowchart for the process described here and determine theoretical flow time from the time of order until the time of payment collection. Assume no waiting over the course of the process. b) Suppose that each order consists of two dozen cookies. Assume that although the mixing bowl can accommodate dough for two dozen cookies at a time, the oven can accommodate only one tray of one dozen cookies at a time. As before, spooning each tray takes 2 minutes, and both trays must be cooled prior to boxing the cookies for customer pickup. Draw a modified flowchart and determine theoretical flow time. Consider the effect on flow time of the following possible alternatives to the system: 1. Buying a second oven that can bake one tray of one dozen cookies. 2. Buying a second oven that can hold two trays of one dozen cookies each. 3. Buying a faster convection oven that can bake one dozen cookies in 6 minutes instead of 9 minutes?.

4.3

Wonder shed Inc. produces steel sheds. The company produces two models, standard and deluxe. The production process for the two models is identical and is depicted in figure 4.1 the activity times and number of visits for the two models are listed in table 4.8. a. Compute the theoretical flow time for a deluxe shed.

b. Compute the theoretical time for a mix of 75% standard and 25% deluxe sheds. c. The company...

Please join StudyMode to read the full document