Week 2: Inventory Turns, Executive Shirts, Process Re-engineering, Worker flexibility and productivity, Queuing ModelNames: ___________________________________Executive Shirts Company Assignment,...

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Week 2: Inventory Turns, Executive Shirts, Process Re-engineering, Worker flexibility and productivity, Queuing Model Names: ___________________________________ Executive Shirts Company Assignment, write name/names Please use Pages 2 to 9 of this document (have questions and some partial answers) to write your answers to the questions and to show your work. In preparing your answers, assume little or no variation in operation times and that a management system is in place that is capable of maintaining average inventories as described in the current and proposed systems. Executive Shirts Company Assignment Review the HBS case Executive Shirts Company and answer all nine Assignment Questions in this document. (Please ignore the questions on the last page of the case.) Note that this document provides a few partial calculations to assist you with this HW. Please make sure to state any assumptions you make in answering questions. A. Flow Diagram (or Process map): See Case for details Note 1: WIP inventories are not shown. Note 2: The two numbers in brackets for each stage (labor time per shirt, number of workers) are from Exhibit 3 in the case. Where there are multiple workers assigned to a stage, assume that the workers work in parallel independently of each other. For example, for Make Collar, (3.9, 8) means there are 8 workers assigned to this stage, and each can make collar for one shirt in 3.9 minutes. Thus, 8 of them can make collars for 8 shirts in 3.9 minutes. Note 3: The first stage (Cut Patterns) performs the following tasks: (i) roll out layers of fabric (one layer at a time, up to 60 layers, could be a mix of different colors) on the cutting table, and (ii) layout patterns (for up to 8 different sizes, a pattern has all different pieces for a shirt), cut and move the pieces from the table. This operation is performed by 4 workers who work as a team. It means, all 4 workers work together to perform a task. For example, it takes 1.5 minutes for team of all 4 to layout one layer of fabric. It takes 30 minutes for team of 4 to cut. B. Analysis of the Current Cutting Operation (Exbt.2): Capacity 60 layers of cloth (“L=60”) Patterns for 8 shirts (8 shirts per layer, may be of different sizes) Takes 1.5 minutes to roll out each layer Takes fixed 30 minutes to cut, takes same amount of time regardless of the number of layers Cutting takes: (1.5 x L + 30) minutes for L layers Number of shirts in L layers = 8L shirts Cutting takes: (1.5 L + 30) minutes to cut pieces for 8L shirts Cutting takes: (1.5 L + 30)/60 hours to cut pieces for 8L shirts [Note 60 minutes per hour] Hourly production capacity with L layers = 8 (1.530)/60 L L æö ç÷ + èø shirts per hour Hourly production capacity for L equal to 60 = 8*60 (1.5*6030)/60 æö ç÷ + èø = 240 shirts Daily production capacity for L equal to 60 = 240 (shirts/hour) x 8 (hours/day) = 1,920 shirts per day Assignment Question 1: Assume that the company policy requires that number of layers L must be an integer multiple of 5 but cannot exceed 60; that is, L can take any value in the set (5, 10, 15, 20, ...,60). Show that the minimum L needed is 10 to get the daily production capacity of 800 shirts per day? Answer: (Show your calculations to support your answer.) C. Analysis of post-cutting stages (15 stages, from Make Collar to Package): Assignment Question 2: Calculate the daily production capacity of each post-cutting stage. (Please fill in the numbers in the table below). Which stage is the bottleneck? What is the process capacity? Stage Description Daily Capacity (show your calculations), assume 480 minutes/day 1 Make Collar 480 (min/day) 8 workers 3.9 (worker-min/shirt) x = 984.61 2 Make Cuffs (480/2) x 4 = 960 3 Make Sleeves 4 Make Front 5 Make Back 6 Join Shoulders 7 Attach Collar 8 Attach Sleeves 9 Stich Sleeves 10 Sew Seam 11 Attach Cuffs 12 Hem Bottom 13 Inspect 14 Iron 15 Package Q2.a: Which stage is the bottleneck (the stage with the lowest daily production capacity)? Q2.b: What is the daily capacity (shirts per day) of the process? Assignment Question 3: What is the average flow time in days (from the start of Cutting to the completion of Packaging) given the production rate of 800 shirts/day and the inventory data in Exhibit 3 of case? Inventories (Three batches per worker except for Cutting, 60 shirts per batch; Exhibit 3) Type of Operation Number of Workers Number of Machines Average WIP (number of 60 shirt batches) Cutting 4 1 16 batches Sewing 48 48 144 batches Inspect 4 - 12 batches Iron 4 4 12 batches Pack 4 - 12 batches Total WIP Inventory = 196 batches x 60 shirts/batch = 11,760 shirts Hint: Refer to the Toy Manufacturing Example to understand how to find the average flow time given the inventory and the flow rate. D. Planning for Custom Shirts: Increasing the capacity of Cutting Management requirements for custom shirts Delivery: Within 5 days Amount (Production/day): 100 shirts / day Order Quantity: 1 to 5 shirts of a size per order Assignment Question 4: (The purpose of the analysis in this question is to demonstrate that the existing cutting machine does not have enough time to cut pieces for 100 shirts per day of custom shirts. Note that each custom shirt order is for one size and for up to 5 shirts per order). In the cutting operation for custom orders, assume that it still takes 1.5 minutes per layer and fixed 30 minutes for cutting. Each layer will have a pattern for only one shirt and there could be up to 5 layers depending on the order size. How many minutes of cutting time per day is needed on the existing cutting machine to cut fabric for 100 custom shirts per day? To answer this question, assume L = 5 and one shirt per layer. Insight: If your answer to the above question is more than 480 minutes, then clearly we need another cutting machine. Moreover, the fixed component of the cutting time for the new machine should be faster than 30 minutes. Assignment Question 5: Compute the daily cutting capacity of the new “low play” laser cutting machine assuming: (1) L = 5 and 1 shirt per layer, and (2) L = 1 and 1 shirt per layer. [Note: As the case states, laying out a pattern and cutting takes 2.5 minutes for up to 5 layers. You can assume that the time to roll out layers for this machine is negligible.] 5a. Daily cutting capacity with 5 layers per cut? 5b. Daily cutting capacity with 1 layer per cut? E. Planning for Custom Shirts: Mike’s and Ike’s Plans (i) Mike’s Plan: Two cutting machines, a common line for post-cutting stages Cc · Post cutting operations: Common line for both products · For regular cutting: Assume L = 10 and 8 shirts per layer ( 80 shirts per cut · For custom cutting: Assume L = 5 and 1 shirt per layer ( 5 shirts per cut · From Regular Cutting to first stage in Post-Cutting: Each batch of 10 broken into 2 batches of 5 · From New Cutting Machine to first stage in Post-Cutting: Shirts moved in batches of 5 · All Post-cutting operations: Shirts handled (stored, moved) in batches of 5 shirts · Post-cutting inventories: WIP inventories in batches of 5 shirts · See Exhibit 5 for WIP inventories Assignment Question 6: Calculate the average flow time (called manufacturing lead time or MLT in the case) for shirts for Mike’s plan. Assume flow rate of 900 shirts per day (800 regular and 100 custom). Please use the numbers in Exhibit 5 to calculate the average inventory. (ii) Ike’s Plan: Two cutting machines, two separate lines Regular shirts Line: · One less worker on each post-cutting stage · Cutting: L = 60 and 8 shirts per layer · Batch size of 60 shirts · WIP data in Exhibit 6 Custom shirts Line: · One worker per station · Cutting: 1 shirt at a time (L=1 and 1 shirt per layer) · Batch size of 1 shirt · WIP of 2 shirts for Cutting machine and 3 shirts per worker for post-cutting operations Assignment Question 7: Convince yourself that the daily capacity for regular shirts in Ike’s plan is 720 shirts per day. How much overtime (in minutes) per day is needed to meet the target of 800 shirts per day? Assume that the overtime is in multiple of 60 minutes. [To answer this question, assume that overtime is used for all workers on the line. It is certainly possible to run the line with fewer workers in overtime, and we will discuss this aspect in class.] Assignment Question 8: (a) Calculate the daily production capacity of the custom line, (b) Calculate the average flow time for the custom line assuming production of 100 shirts per day. Q8.a: Daily production capacity of the Custom Line: Q8.b: Average Flow Time (in days) for custom shirts: F: Recommendation Assignment Question 9: Compare Mike’s and Ike’s plans in terms of performance [cost, quality, time, flexibility] for both regular shirts and custom shirts and demand forecasts. Which plan would you recommend? Why? Summary of numerical/short answers: Please write your answers in the table below. Question Description Your Answer 1 Min L 10 2 a Bottleneck Stage 2 b Process Capacity 3 Flow Time in days for the current process 4 Minutes of cutting Time for customs shirts 5 a Capacity of new machine with L = 5 5 b Capacity of new machine with L = 1 6 Average flow time in Mike’s plan 7 Overtime for regular shirts in Ike’s plan 8 a Daily Capacity of Custom Line in Ike’s plan 8 b Average flow time for custom line in Ike’s plan Make Back Cut Patterns Make Collar Make Cuffs Make Sleeves Make Front (3.9,8) (2.0,4) (0.65,2) (2.50,6) (1.70,4) Stitch Sleeves Attach Sleeves Attach Collar Sew Seam Join Shoulders (0.66,2) (1.65,4)
Answered 1 days AfterOct 24, 2022

Answer To: Week 2: Inventory Turns, Executive Shirts, Process Re-engineering, Worker flexibility and...

Banasree answered on Oct 26 2022
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Week 2: Inventory Turns, Executive Shirts, Process Re-engineering, Worker flexibility and productivity, Queuing Model
Names: ___________________________________
Executive Shirts Company Assignment, write name/names
Please use Pages 2 to 9 of this document (have questions and some partial answers) to write your answers to the questions and to show your work. In p
reparing your answers, assume little or no variation in operation times and that a management system is in place that is capable of maintaining average inventories as described in the current and proposed systems.
Executive Shirts Company Assignment
Review the HBS case Executive Shirts Company and answer all nine Assignment Questions in this document. (Please ignore the questions on the last page of the case.) Note that this document provides a few partial calculations to assist you with this HW. Please make sure to state any assumptions you make in answering questions.
A. Flow Diagram (or Process map): See Case for details
Note 1: WIP inventories are not shown.
Note 2: The two numbers in brackets for each stage (labor time per shirt, number of workers) are from Exhibit 3 in the case. Where there are multiple workers assigned to a stage, assume that the workers work in parallel independently of each other. For example, for Make Collar, (3.9, 8) means there are 8 workers assigned to this stage, and each can make collar for one shirt in 3.9 minutes. Thus, 8 of them can make collars for 8 shirts in 3.9 minutes.
Note 3: The first stage (Cut Patterns) performs the following tasks: (i) roll out layers of fabric (one layer at a time, up to 60 layers, could be a mix of different colors) on the cutting table, and (ii) layout patterns (for up to 8 different sizes, a pattern has all different pieces for a shirt), cut and move the pieces from the table. This operation is performed by 4 workers who work as a team. It means, all 4 workers work together to perform a task. For example, it takes 1.5 minutes for team of all 4 to layout one layer of fabric. It takes 30 minutes for team of 4 to cut.
B. Analysis of the Current Cutting Operation (Exbt.2): Capacity
60 layers of cloth (“L=60”)
Patterns for 8 shirts (8 shirts per layer, may be of different sizes)
Takes 1.5 minutes to roll out each layer
Takes fixed 30 minutes to cut, takes same amount of time regardless of the number of layers
Cutting takes: (1.5 x L + 30) minutes for L layers
Number of shirts in L layers = 8L shirts
Cutting takes: (1.5 L + 30) minutes to cut pieces for 8L shirts
Cutting takes: (1.5 L + 30)/60 hours to cut pieces for 8L shirts [Note 60 minutes per hour]

Hourly production capacity with L layers =
8
(1.530)/60
L
L
æö
ç÷
+
èø
shirts per hour
Hourly production capacity for L equal to 60 =
8*60
(1.5*6030)/60
æö
ç÷
+
èø
= 240 shirts
Daily production capacity for L equal to 60 = 240 (shirts/hour) x 8 (hours/day) = 1,920 shirts per day
Assignment Question 1: Assume that the company policy requires that number of layers L must be an integer multiple of 5 but cannot exceed 60; that is, L can take any value in the set (5, 10, 15, 20, ...,60). Show that the minimum L needed is 10 to get the daily production capacity of 800 shirts per day?
Answer: (Show your calculations to support your answer.)
Currently = L = 60 = 1920 shirts.
If we plan for 800 shirts per day
Then minimum L will be = (60 * 800)/1920 = 25
Where L is a integer of 5, but > 60.
Now, with given data of current production, if we plan of L = 10, result shirts will much less than 800 nos.
C. Analysis of post-cutting stages (15 stages, from Make Collar to Package):
Assignment Question 2:...
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