PROCESS ANALYTICS HANDBOOK

XLRI JamshedpurRajiv Misra

PRODUCTION PLANNING AND CONTROL

Team No 8Name of Group Members

Shirish Pathak B14050Ashutosh Mathur B14015

Tarun Bagri B14055

Nikhil Arora B14159

Name of file to be mailed to rajiv @xlri.ac.in Format: BM_PPC_Team X_2013 where

X is the team no PROCESS ANALYTICS HANDBOOKProblem 1: Three Step Process Assignment Questions

Process 1

To begin, consider the three-step process model in the Process 1 tab. The process is staffed by three workers: Alice is assigned to step A, Bob is assigned to step B, and Charlie is assigned to step C. Please answer the questions below.1. What is the bottleneck of this process?

Bob2. What is the cycle time of this process?

5 Min3. What is the capacity of this process?

12 per hr4. What is the throughput time or a rush order (that is, an order arriving when the system is empty that is moved through the process without delay)?

10 Min5. What is the labor utilization of each worker?

Alice:60%, Bob:100%, Charlie:40%6. What is the average labor utilization of the workers? 66.67%Process 2

Now that you have finished Process 1, consider the same process, but assume we assign Betty, an additional worker, to a step B. Betty and Bob are equally qualified, and they are told to split the work of step B (working simultaneously complete the 5 minutes of work on a unit in half that time).1. Before doing any calculations, which process metrics would you expect to change relative to Process1Cycle time, Throughput time2. What is the cycle time of this process?

3 Min3. What is the capacity of this process?

20 per hr.4. What is the throughput time for a rush order (that is, an order arriving when the system is empty that is moved through the process without delay)? 10 min5. What is the labor utilization of each worker?

Alice: 100%, Bob: 83%, Betty: 83%, Charlie: 67%6. What is the average labor utilization of the workers?

83.33%7. What have you learned?

Elevating one bottleneck shifts the process bottleneck. Process 3Look at Process 3, a variant of Process 1 ( 3 workers, Alice does step A, Bob step B, and Charlie step C). However, assume that steps A and B can be completed in parallel, as shown in the process diagram. (In parallel means that Alice can work on her component at the same time as Bob works on his component. For example, Alice could be finishing a table top at the same time Bob is finishing the four legs, and Charlie could be assembling the table by attaching the legs to the table top.)1. Before doing any calculations, which process metrics would you Process I?

Cycle time, throughput time2. What is the bottleneck of this process?

Workstation B3. What is the cycle time of this process?

5 Min4. What is the capacity of this process?

12 per hr5. What is the throughput time for a rush order (that is an order arriving when the system is empty that is moved through the process without delay)?7 Min6. What is the labor utilization of each worker?

Alice: 60%, Bob: 100%, Charlie: 40%

7. What is the average labor utilization of the workers?66.67%8. What have you learned?

Throughput time can be reduced by doing activities in parallel.Problem 2: Four Step Process Assignment Questions

Process 1To begin, consider the four step process model in the Process 1 tab.

1. Calculate the amount of the time it would take to get a rush order through the process.

14.5 Min2. Calculate the capacity of the process.

12 per Hr3. Calculate the labor content of the process.

A: 100%, B: 60%, C:50%, D: 80%4. Calculate the average labor utilization.

72.5%Process 2

For the process 2, assume that you have hired an additional worker (i.e., a fifth for the process). This new worker is cross trained at every step in process (can perform any of the 4 steps or any portion of any of the four steps). Inventory is permitted between steps so that the cross trained worker can move around freely. Assume no transportation time in moving from one step to another.

1. At which step (s) does the worker spend the majority of his or her time?

Workstation A2. What is the impact on performance?

Capacity increased to 20 per hr, Utilization increased to 96.67%Process 3

For Process 3, you have the opportunity to send each of your four specialists to get additional training in the other process steps. As a result of this training program, you will have five workers available to you, each one cross-trained at each of the four process steps.1. What benefits do you expect as a result of this additional training?Capacity increased to 20.69 per hr, Utilization increased to 100%Process 4

Go to Process 4, a variant of Process 1. Your analysis was done with the assumption that no inventory would be allowed to build up between steps. Answer these questions without that assumption.1. How would performance change if this restriction were relaxed? That is, what would impact of allowing inventory to accumulate between steps?Capacity changed to 12 per hr, utilazation to 72.5%Problem 3: Sub Assembly Assignment Questions

Consider the following process in the Process 1 tab. All steps (A, B, C, D) are necessary to create each finished unit. Each step employs a single worker who is not cross-trained for any other processing times listed represent the amount of time each worker spends on a single unit. There is not variability in processing times.Process 1

1. What is the fastest that a rush order can go through the process?

35 Min2. Working 8 hours a day, what is the daily capacity?

32Process 2For the next two questions, consider a fifth step added to the process along with a fifth worker. The fifth step, Step E, is done after Step C, and before Ste D, as depicted Process 2. All steps (A, B, C, D, and E) are necessary to create each finished unit. Processing times are shown for each process step.3. What is the fastest that a rush order can go through the process?

45 min4. Working 8 hours a day, what is the daily capacity?

32Problem 4: Batch Processing Assignment Questions

Consider the following three-step worker- paced line in the Process 1 tab. Each step employs a single worker who is not cross- trained for any other step. The setup represents the amount of time the worker spends setting u e machine hatch. No units can be processed during setup. The run time represents the amount of time it takes the worker to process a single unit. When a worker completes a batch, he or she hands it off to the next stage.Process 1

1. If only 10-unit batches are produced, what is the average capacity of the process per 8-hour502. At what batch size does the bottleneck move? That is, at what batch size are there two steps that are the bottleneck?

5Problem 5: Random Variation Assignment Questions

Consider the six-step process in the Process 1 tab, where the processing time for each step is uniformly distributed. Processing times can range from 12 to 18 minutes (any value in that range is as likely to occur as any other in that range).Process 1

1. If inventory were permitted to accumulate throughout this process, what impact would you expect on capacity (as compared to the process without inventory)?

Capacity would increase in the case with inventory compared to case without inventory as it would act as a buffer in case of uncertainty2. If you could add one inventory buffer, where would you add it to maximize capacity?

Would add inventory buffer before lowest workstation utilization hence workstation C to make sure that low utilization is not due to material unavailability3. If you added a second unit of buffer to the same location as the first, what would be the incremental impact on capacity of the second unit as compared with the first unit?

Incremental impact of the second inventory buffer would be less as compared to the first unit

Problem 6: Inventory Assignment Questions

consider the four-step worker paced line in the Process 1 tab. Each step employs a single worker who is not cross-trained for any other step. The processing times listed represent the amount of time each worker spends on a single unit. There is no variability in processing times. Assume that all workers begin to work on the next unit as soon as they can.

Process 1

1. Assume that inventory is not permitted to accumulate - i.e., a unit cannot be passed to the next stage until the worker receiving the unit is ready for it. What is the capacity of the process?3 per hr2. If inventory were allowed to accumulate in this process, where would it accumulate?

1. Between A and B.

2. Between C and D

3. If inventory were allowed to accumulate, how would capacity be affected?No impact as there is no variability in the process time4. If inventory were allowed to accumulate, how would average throughput time be affected?Average throughput time will increase as more material will be in process due to inventory buffer but processing time will remain same.From this point forward, assume that inventory is not permitted to accumulate, and that work cannot be passed to the next stage until the worker receiving the unit is ready.5. If a fifth worker were added to the process, what would the maximum capacity be? Assume that you can add the fifth worker to anyone of the four tasks, that the worker is not cross trained to do any of the other tasks and that the fifth worker works at the same rate as the original worker doing that task. 4 per hr6. Instead, if a fifth worker who was cross trained for all tasks were added to the process, what would the new capacity be? Assume that this fifth worker incurs no travel time in moving between Compare the labor utilization of the worker at Step 1 in the original situation (four workers, no inventory) and the situation with the addition of the cross-trained fifth worker from the Four Step Process problem. How does it change?New capacity 5.14 per hr. Utilization would increase from 62.5% to 85.71%Problem 7: Krunchy Kreme Assignment Questions

Krunchy Kreme, marking its famous doughnuts, begins with the three-step process shown in Process 1. One dedicated worker mixes the dough and creates the doughnut shape from it. Batches of doughnuts from the Shaping stage are processed in one of two identical machines in the third step, staffed by one worker each. (Ignore the remaining steps in the process, such as frying and packing, because they have ample capacity.) Assume that all setups are done by the workers. A setup must be performed in each step of the process before every batch. Also, assume that each worker is busy during the run time of his or her operation.Process 11. Suppose that the batch size is 50 doughnuts. What is the capacity in an eight hour day?

5002. What is the average utilization of these four workers?

84.21%3. If Krunchy Kreme decides to change batch sizes, for what range of batch sizes is mixing the bottleneck?Workstation A & Workstation B: Batch size 28.57Workstation A & Workstation C: Batch size 81.81

Workstation C & Workstation B: Batch size 175

Problem 8: Random Variation with Long Chains Assignment

Process 1 For the processes in this assignment, we will explicitly account for variability in process time with those process times distributed according to a uniform distribution. Thus, a process time of 5 1 minutes/unit indicates that there is equal probability that the process (machine or person) will have a process time of anywhere from four to six minutes/unit. There are no setups.

1. Consider an eight-workstation in-series line, with all workstation processing time at 5 1 minutes per unit. Allocate 22 units of buffer capacity to this line so as to maximize average output. What is the best such allocation?

To maximize the average output allocate equal units before each workstation. Hence from workstation 2 allocate 3 units each and remaining one extra units before workstation 8 as more variability will be there.For the rest of this part, consider four different production ,lines consisting of in-series workstations with no buffers between stations. The numbers under e workstation represent the process time per unit, in minutes.

2. Assuming that Line A has been operating for a while, the expected capacity of Line A is a.

a. Less than 6 units per hour

b. Greater than 6 units per hour

c. 6 units per hour

d. Cannot be determined 3. Comparing the utilization of Machine A2 of Line A to that of Machine B3 of Line B,

e. A2 has the same utilization as B3f. A2 has a lower utilization than B3

g. A2 has a higher utilization than B3

h. Cannot be determined

4. Comparing the capacity of Line B to that of Line C,

i. Line C has a higher output than Line Bsj. Line C has a lower output than Line Bs

k. Line C has an output equal to that of Line B

l. Cannot be determined5. Comparing the capacity of Line C to that of Line D,

m. The output of Line D is lower than line C,

n. The output of Line D

o. The output of Line D is higher than Line Cs

p. Cannot be determinedProblem 9: Rework and Scrap Assignment Questions

Imagine a three-workstation worker-paced line with task times 7, 6, and 8 minutes, respectively. In the previous problems, a 100% yield was assumed - i.e., no defects. The present problem will explicitly consider the impact of nonzero defect rates. In particular, assume that the first workstation has an 8% defect rate and that the second workstation has a 12% defect rate. The third workstation, in contrast, generates no defects. For problems 1 to 4, assume that all defective units are scraped.

Part A

1. What is the capacity of this process?

6.44 per hr2. Where is the bottleneck?

Workstation A3. Is the utilization of the bottleneck step 100%? If so, why? If not, why not?

No. Because of the scrap the process utilization decreases4. What is the yield of the process (the ratio of good process)?

80.96Part BNow assume that the second workstation feeds its defects to a rework station that performs a delicate and lengthy task of disassembling the product and repairing it. Thus, it requires a relatively long time (here, 40 minutes on average) to fix defects. There is an inventory buffer in front of this rework step to accommodate for the unlikely case that there are several defects in a row. While time- consuming, it still is successful only 90% of the time. When rework is successful, the rework station passes the now- good unit to the third workstation in the line. If it is not successful, the product is scrapped.The third workstation, receiving reworked units, now has an average task time of 9 minutes.

1. What is the capacity of this process?

6.222. Where is the bottleneck?

Workstation C3. Is the utilization of the bottleneck step 100%? If so, why? If not, why not?

No. Because of the rework of the scrap material generated4. What is the yield of the process (the ratio of good finished product to items started in the process)?

90.896Name of Group Members

GENERAL QUESTIONSRefer to the discussion on the CARD GAME.Each member to prepare 3 cards each for the game