Dooly County Doughnuts Case study

Please note that same case is posted with incomplete answer.

1) Calculate the capacities at each step of the doughnut making process. What is the bottleneck of the process? What is the overall capacity of the process?

2) How would your answers in question 1change if the batch size was changed to 16 lbs.? You may assume that the cycle time and the setup time do not change due to the change in batch size.

3) If Johnson decides to keep the batch size at 8 lbs. and instead decides to focus on reducing the setup time of the extrusion process, by how much should he reduce his setup time in order to meet his demand?

4) If Johnson decides to invest in 6 cutters, what setup time would be needed for Johnson to meet demand with 6 cutters for the standard 8-lb. batch?

5) What would you recommend Johnson do?

Dooly County Doughnuts Dewey Johnson sat in his office contemplating the past year of operation of his Dooly County Doughnuts (DCD) shop located in Vienna, Georgia. DCD served walk-in customers, and also made doughnuts to be stocked at local grocery stores and coffee shops. Over the past year, Johnson had spent considerable time trying to increase sales but had not spent much time focused on the operations of the shop. Through his window, he could see the line for doughnuts extending well into the parking lot. While he was pleased with the results of his sales push, he realized he needed to assess his capacity and maybe consider expansion. Product Sales Doughnut production at DCD was currently limited to a single 8-hr. shift per day, 7 days per week. During peak hours, Johnson maintained a staff of 3 to 4 employees that was more than capable of running the highly automated process without any additional slowdowns. Currently Johnson sold, on average, 1,100 dozen doughnuts per day of all varieties. Production The doughnut-making process consisted of four stages: (1) batching, (2) mixing, (3) production, and (4) customizing. See Exhibit 1 for a layout of the process. Stage 1: Batching : The batching stage started with an operator combining all the ingredients in a mixing bowl. Water was added first, followed by all of the dry ingredients contained in DCD's proprietary doughnut recipe. It took 2 min. to place the ingredients in the mixing bowl. The equipment could handle batches of dough of various sizes ranging from just 2 lb. to over 20 lb. Each doughnut required exactly 2 ox of dough. Stage 2: Mixing Once all of the ingredients had been combined, the batch was placed in the mixer. The mixing process took 2.5 min. per batch, and the mixer turned off automatically at the end of the process. The store had 2 mixers Stage 3: Production The production stage consisted of three steps: (1) extruding. (2) frying, and (5) glazing. Extruding After mixing, the dough was transferred into the extrusion machine container, There the dough was pushed through cylindrical cutting attachments (cutters) that extruded the dough into individual pieces that would eventually be turned into the finished doughnut. The machine used a set of 3 cutters. Each cutter could extrude dough at a rate of 18 extrusions per minute. Therefore, using 3 cutters, the machine made doughnuts at a rate of 54 doughnuts per minute. The machine had to be set up before each batch was extruded. This included cleaning the machine from the previous batch, cleaning the cutters, and adding the fresh batch of dough. The setup took approximately 1.5 min. per batch. Frying After being formed by the extruder, the doughnuts were dropped directly into hot shortening in a long and narrow fryer. The fryer en continuously and had sufficient space to handle as many doughnuts as the extrusion machine provided. The doughnuts stayed in the fryer for 20 sec. Surface rods pushed the doughnuts through the fryer Glazing The fried doughnuts cooled on a conveyor for 45 sec. before passing through the glazing machine. The cooling conveyor and glazer also ran continuously and had sufficient space to handle as many doughnuts as the extrusion machine provided, so finished doughnuts were produced at the rate at which they were made the extrusion machine. Stage 4: Customizing In the customizing stage, doughnuts were customised to either be placed for sale at the counter or boxed for specific customer orders. This step involved adding a range of different toppings from traditional toppings like sprinkles to unique toppings such as the Ellis Rothers' world-famous pecans from right up the road. One employee handled the customization step. On average, the employee was able to customize two doughnuts every 3.5 sec. The Problem Johnson had noticed a disturbing trend. Each day, DCD was tuming away customers because it was unable to make enough doughnuts to meet demand. He needed to find a way to increase his capacity. One change Johnson had considered was to increase the batch size. The standard batch size that he had instructed his employees to use was 8 lb. The mixer and the extruder could handle much larger batches, however, he wanted to keep the batches as small as possible so as to not wear out his equipment prematurely. Alternatively, the staff had suggested there might be a way to keep the current batch sixe, and instead, focus on improving some of e more manual steps in the current process to increase capacity. Finally, Johnson knew that the extruder could be muxlified to operate with 6 cutters and increase the item which doughnuts could be extruded. He was cautious regarding this option through since setting up the extruder for 6 cutters would take longer than the setup time required for the existing 3 cutters, PIC.COLLAGE Dooly County Doughnuts Dewey Johnson sat in his office contemplating the past year of operation of his Dooly County Doughnuts (DCD) shop located in Vienna, Georgia. DCD served walk-in customers, and also made doughnuts to be stocked at local grocery stores and coffee shops. Over the past year, Johnson had spent considerable time trying to increase sales but had not spent much time focused on the operations of the shop. Through his window, he could see the line for doughnuts extending well into the parking lot. While he was pleased with the results of his sales push, he realized he needed to assess his capacity and maybe consider expansion. Product Sales Doughnut production at DCD was currently limited to a single 8-hr. shift per day, 7 days per week. During peak hours, Johnson maintained a staff of 3 to 4 employees that was more than capable of running the highly automated process without any additional slowdowns. Currently Johnson sold, on average, 1,100 dozen doughnuts per day of all varieties. Production The doughnut-making process consisted of four stages: (1) batching, (2) mixing, (3) production, and (4) customizing. See Exhibit 1 for a layout of the process. Stage 1: Batching : The batching stage started with an operator combining all the ingredients in a mixing bowl. Water was added first, followed by all of the dry ingredients contained in DCD's proprietary doughnut recipe. It took 2 min. to place the ingredients in the mixing bowl. The equipment could handle batches of dough of various sizes ranging from just 2 lb. to over 20 lb. Each doughnut required exactly 2 ox of dough. Stage 2: Mixing Once all of the ingredients had been combined, the batch was placed in the mixer. The mixing process took 2.5 min. per batch, and the mixer turned off automatically at the end of the process. The store had 2 mixers Stage 3: Production The production stage consisted of three steps: (1) extruding. (2) frying, and (5) glazing. Extruding After mixing, the dough was transferred into the extrusion machine container, There the dough was pushed through cylindrical cutting attachments (cutters) that extruded the dough into individual pieces that would eventually be turned into the finished doughnut. The machine used a set of 3 cutters. Each cutter could extrude dough at a rate of 18 extrusions per minute. Therefore, using 3 cutters, the machine made doughnuts at a rate of 54 doughnuts per minute. The machine had to be set up before each batch was extruded. This included cleaning the machine from the previous batch, cleaning the cutters, and adding the fresh batch of dough. The setup took approximately 1.5 min. per batch. Frying After being formed by the extruder, the doughnuts were dropped directly into hot shortening in a long and narrow fryer. The fryer en continuously and had sufficient space to handle as many doughnuts as the extrusion machine provided. The doughnuts stayed in the fryer for 20 sec. Surface rods pushed the doughnuts through the fryer Glazing The fried doughnuts cooled on a conveyor for 45 sec. before passing through the glazing machine. The cooling conveyor and glazer also ran continuously and had sufficient space to handle as many doughnuts as the extrusion machine provided, so finished doughnuts were produced at the rate at which they were made the extrusion machine. Stage 4: Customizing In the customizing stage, doughnuts were customised to either be placed for sale at the counter or boxed for specific customer orders. This step involved adding a range of different toppings from traditional toppings like sprinkles to unique toppings such as the Ellis Rothers' world-famous pecans from right up the road. One employee handled the customization step. On average, the employee was able to customize two doughnuts every 3.5 sec. The Problem Johnson had noticed a disturbing trend. Each day, DCD was tuming away customers because it was unable to make enough doughnuts to meet demand. He needed to find a way to increase his capacity. One change Johnson had considered was to increase the batch size. The standard batch size that he had instructed his employees to use was 8 lb. The mixer and the extruder could handle much larger batches, however, he wanted to keep the batches as small as possible so as to not wear out his equipment prematurely. Alternatively, the staff had suggested there might be a way to keep the current batch sixe, and instead, focus on improving some of e more manual steps in the current process to increase capacity. Finally, Johnson knew that the extruder could be muxlified to operate with 6 cutters and increase the item which doughnuts could be extruded. He was cautious regarding this option through since setting up the extruder for 6 cutters would take longer than the setup time required for the existing 3 cutters, PIC.COLLAGE