DSC 335, Spring 2014
Kristen’s Cookies Precase
1. It will take 26 minutes to fill one rush order (6+2+10+5+2+1= 26 minutes). Gantt chart is also attached.
2. The cycle time is 10 minutes because the bottleneck is the time they have to wait for the cookies to bake in the oven. They cannot continue the cookie process without baking and the lack of room in the oven or additional ovens are the constraints that are limiting the total operation. The capacity of the operation would be 6 orders per hour (60 minutes/ 10 minutes= six orders), so that means you could fill 24 orders in one night (6 orders an hour * 4 hours). This answer does assume that every order only asks for one dozen each, for example, if one customer orders two dozen, you would only be able to fill 23 orders because that order would require using the oven twice.
3. The amount of labor per dozen for 1 order is 8 minutes per dozen (mixing and scooping takes 8 minutes) for Kristen and 4 minutes for Kristen’s roommate per dozen (the real work she does, the time she spends waiting is negligible so the 1 minute to load, 2 minutes to package and 1 minute to accept the payment). Kristen’s roommate only does slightly less work per dozen when they are all similar because she’ll only accept the payment once, so for two dozen she would do 3.5 minutes, and three dozen she would do 3.33 minutes per dozen. Kristen does the same amount of work per dozen when they are all different. When the cookies have similar ingredients, Kristen does less work because she doesn’t have to continue mixing for each dozen. If it’s two similar dozens of cookies, Kristen does 5 minutes of work per dozen (6 minutes of mixing, 2 minutes of scooping * 2 times/2). When it’s three similar dozens of cookies, Kristen does 4 minutes of work per dozen (6 minutes of mixing, 2 minutes of scooping * 3 times/3). If it’s two similar dozen and one different, she will do 6 minutes of work per dozen (6 minutes of mixing* 2 times, 2