While an effective document revision and control scheme is useful for com- municating new methods and procedures, it is often not sufficient, especially when procedures undergo the significant changes often resulting from the DMAIC process. Even when procedural changes are relatively narrow in scope, training is quite beneficial in communicating the changes and pre- venting problems or misinterpretations of the new procedures. This training can be as simple as a quick meeting with the operational personnel at their workstations or a detailed multisession training, such as may be required for new equipment or to teach customer-friendly communication skills.
Topics for training include the lessons learned during the DMAIC process, the key process factors, and their interactions, in addition to the new proce- dures themselves. Including these lessons learned is really helpful to the stake- holders, particularly the operational personnel, so they understand why the changes were necessary and how the conclusions were developed.
The training should include operational personnel, process owners, and other stakeholders (including suppliers, if appropriate). Most, if not all, of these stakeholder groups were represented on the team and included in data collection or analysis, so this part of the training will provide a good con- clusion to their efforts.
For the training to be effective, it should be targeted to the current skill set of the audience, and include a means of assessing the knowledge transfer to each individual. The format of these evaluations depends on the criticality and complexity of the subject matter. In some cases, workshops are useful for employees to practice the newly acquired skills; in cases of critical safety or quality issues, employees may have to demonstrate proficiency through writ- ten or on-the-job testing.
Participants should be evaluated immediately at the end of the training and at a stipulated time later. This posttraining evaluation gauges the longer-term retention of the material and may demonstrate a need for follow-up training or a change in training format to more effectively target the audience. Of course,
the best means of evaluating the impact of the training is to measure the changes in behavior resulting from the training. Are people using the new skills? To what degree?
Measure Bottom-Line Impact
A key part of the control stage is to continuously monitor the effects of the process improvement. This is a critical part of DMAIC that was often ne- glected in past improvement strategies.
The control plan should contain provisions for monitoring the process output either as a method of control or a sampling audit. Generally, the process owner (the operational personnel) will be responsible for the ongoing tracking of the applicable performance metric. This activity should continue for as long as necessary, as often as necessary, to establish the underlying process capability.
Often sampling is fairly frequent in the beginning, and tapers off once the process has proven stable and capable of achieving the requirements. See the statistical process control charting section in Part 3 for general discussion of sampling frequency and sample sizes necessary to detect process shifts.
As part of this control stage, the Black Belt will assume responsibility for verifying the operational-level controls done by the process owners. In addi- tion, the Black Belt will audit the process on a regular (for example, monthly) basis for the first year. The audit should include observation of process pro- cedures and controls, as well as sampling or reviewing the results of data samples to ensure process capability.
If the process exhibits any out-of-control behavior, the Black Belt should be notified, so that a further review can be made to identify its source. In this case, the process control should be investigated, and perhaps tightened, to reduce the occurrence of further process instability. In cases of continued instability, the process should be evaluated for a new Six Sigma project, with a critical review of the initial Six Sigma project report for indication of its failings.
Just as crucial as process control is the ongoing tracking of the financial benefits, usually on a monthly basis as part of cost accounting reports. The fi- nancial reporting must include actual expenditures and savings for each of the items used for project justification in the define stage, as well as expenditures related to the project implementation, such as described in the improve stage.
Savings are calculated based on methods agreed upon in the define stage, and may include actual and predicted annualized estimates. The individual respon- sible for tracking the cost savings should be clearly identified in the control plan.
CHAPTER 8 Control Stage 163
Document Lessons Learned
The results of the Six Sigma project should be documented in a project report.
The project report should include the following information:
The project charter, as a key deliverable in the define stage, introducing the reader to the project’s problem statement, objectives, and plan.
A summary result of each stage of the DMAIC cycle, including the main objectives and results for each stage.
Appendices containing raw data, analysis results, and a timeline of the actual activities for reference.
A listing of the expenditures required to implement the project, including lost capacity, material, or labor.
The cost savings received to date and projected for the next year to three years.
The current status of the process and the control plan for the future.
Recommendations for future projects related to the process.
Recommendations for future project leaders and sponsors, based on lessons learned during this project.
The project report should be circulated to the finance or accounting areas for review of accuracy of the financial information. The project report (and the financial approval) must be presented to the sponsor for formal approval and project close.
In some organizations, Master Black Belt and senior management respon- sible for Six Sigma deployment must also sign off on the reports. It is often a good learning experience for the Black Belts to formally present the findings to management. When other senior management leaders are invited, it provides good exposure to the program and the work of the project teams.
Organizations should adopt some strategy for rewarding Six Sigma teams.
Financial rewards, particularly a percent of the savings, are not necessary, nor encouraged. They send the wrong message and cultivate a culture of short- sighted profiteering or inflated savings at the expense of real improvement.
Instead, teams should be recognized with ceremony and appreciation from management for a job well done. Even project failures should be celebrated for their effort, in the realization that at least some of the stretch goals sought will not be achieved.
In that vein, success stories should be communicated throughout the or- ganization. If frustrations with a process were overcome, that speaks volumes in a language that others are anxious to hear. Project failures should also be noted for their efforts, their partial success, and the lessons learned.
Many companies have found Web-based forums on the company intranet a useful venue for sharing information. Black Belts should be given the op- portunity to share, learn, and grow through one another. The use of technical skills, as well as the softer change management skills necessary for building buy-in, will grow when practitioners have a chance to see their successful application by other teams. It’s truly remarkable how one team’s success can be translated into other processes, even those that seem quite different. White papers, case studies, project reports, as well as chat rooms, are useful for spreading the word and institutionalizing the findings.
Recommended Tools
The following tools (discussed in detail in Part 3) are applicable to the control stage of DMAIC:
Flowchartsandprocess mapsto define the process level activities necessary.
SPC control charts, includingC,Np,P,U,Individual-X,X-Bar, and EWMA charts, andprocess capability indexto verify the effects of the improvement.
Goodness of fit testsandprobability plottingto verify the statistical distributions assumed in the various statistical tools.
R&R studiesto qualify operators’ proficiency on specific measurement equipment.
In addition, the consensus building tools noted at the end of Chapter 4 are also applied, as needed.
Quiz for Chapter 8
1. The control stage of a project should include which of the following objectives?
a. Implementing methods to maintain the improvements.
b. Measuring the financial gain associated with the improvements.
c. Communicating the lessons learned to others in the organization.
d. All of the above.
2. The preferred method of controlling processes is:
a. To detect problems as soon as they occur.
b. Using a control chart.
CHAPTER 8 Control Stage 165
c. To prevent problems from occurring.
d. By training operators to eliminate mistakes.
3. Engineering process control is a method to:
a. Stabilize a process by detecting process shifts.
b. Manipulate process inputs to control process output.
c. Correct for process autocorrelation using algorithmic logic.
d. All of the above.
4. Statistical process control is a method to:
a. Stabilize a process by detecting process shifts.
b. Manipulate process inputs to control process output.
c. Correct for process autocorrelation using algorithmic logic.
d. All of the above.
5. Operational procedures, as a method of process control:
a. Must consider human error.
b. Are as repeatable as automated controls.
c. Cannot be used unless the organization is ISO certified.
d. All of the above.
6. Operational procedures, as a method of process control, can effectively:
a. Standardize the process.
b. Divert resources where needed.
c. Channel customers for expedited service.
d. All of the above.
7. When developing the training objectives for rolling out new process procedures:
a. Include a discussion of the reasons for the change.
b. Stick only to the bare essentials necessary for doing the tasks.
c. Spend a significant amount of the time pointing out problems with the old procedures.
d. None of the above.
8. Training plans:
a. Are often useful, but not necessary.
b. Should be developed solely by the training department.
c. Need to consider the objectives of the organization.
d. All of the above.
9. When evaluating a training session:
a. Initial reactions are most important.
b. Initial reactions are useful, but long-term behavioral changes and results aligned with the objectives are most important.
c. Behavioral changes provide the best estimate of effective training.
d. Testing or exams to quantify the learning of each student are often not helpful.
10. After a training session has been completed, the best way to reinforce the training is:
a. To provide the opportunity to use the new tools or techniques.
b. Through financial reward for improved performance.
c. With examinations.
d. With tight supervision of the employees to ensure that they are using the techniques correctly.
CHAPTER 8 Control Stage 167
1. The nonconformance records for the Painting Department are shown in the table below, where the number reported is the number of defective units for each nonconformance type (cracked, chipped, off-color, wrong color, other):
Example Nonconformance Data.
Month
Total
Shipped Cracked Chipped Off Color
Wrong
Color Other
JAN 3500 7 15 21 12 200
FEB 3124 14 10 28 23 1
MAR 1245 12 5 11 17 9
APR 2020 18 9 7 11 5
MAY 1652 9 14 4 21 9
JUN 2637 11 21 26 9 13
JUL 2543 12 11 19 23 2
168
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Based on this information, which of the following project scope state- ments is best suited to maximize benefit to the company:
a. Reduce the instance of reworks due to wrong color in the Painting Department.
b. Reduce the instance of rework in the Painting Department.
c. Reduce the instance of scrap due to cracks in the Painting Department.
d. None of the above. The ‘‘other’’ category is the largest, and we need to understand its breakdown.
2. For the data shown in question 1, the best estimate for a baseline process defect rate related to wrong color is:
a. 14,166 PPM b. 8,350 PPM c. 141,660 PPM d. 1,670 DPMO
3. The following unit costs can be applied to the data in question 1:
Cracked: $428.25 (cost of scrap material and labor) Chipped: $252.15 (rework cost)
Off color: $275.33 (rework cost)
Wrong color: $117.53 (cost of carrying unordered product in inventory) Based on this information, which of the following project scope
statements is best suited to maximize benefit to the company?
Example Nonconformance Data (continued)
Month
Total
Shipped Cracked Chipped Off Color
Wrong
Color Other
AUG 4042 8 12 12 18 1
SEP 1367 11 13 15 21 7
OCT 3124 21 9 13 40 7
NOV 2645 12 7 6 31 9
DEC 1200 10 4 14 17 8
PART 2 Exam 169
a. Reduce the instance of scrap due to cracks in the Painting Department.
b. Reduce the instance of reworks due to chips in the Painting Department.
c. Reduce the instance of reworks due to off color in the Painting Department.
d. Reduce the instance of reworks due to wrong color in the Painting Department.
4. In addition to the cost information shown in the preceding questions, also consider the following costs and time to deploy the proposed projects, assuming they each have an equal chance of success:
Cracked: $40,000 cost; 30 weeks Chipped: $10,000 cost; 16 weeks Off color: $25,000 cost; 14 weeks Wrong color: $3,000 cost; 10 weeks
Based on this information, which of the following project scope state- ments is best suited to maximize benefit to the company?
a. Reduce the instance of scrap due to cracks in the Painting Department.
b. Reduce the instance of reworks due to chips in the Painting Department.
c. Reduce the instance of reworks due to off color in the Painting Department.
d. Reduce the instance of reworks due to wrong color in the Painting Department.
5. In an initial team meeting, the team should:
a. Establish ground rules and review member responsibilities.
b. Agree on project purpose, scope, plan, and timeline.
c. Establish workable meeting times and locations.
d. All of the above.
6. In a SIPOC analysis, stakeholders are usually:
a. Suppliers.
b. Customers.
c. Suppliers and customers.
d. Not considered in SIPOC.
7. In a SIPOC analysis, customers:
a. Include anyone who receives output.
b. Are defined as the key stakeholders of the process.
c. Are the most important part.
d. Are end-users of the product or service.
8. Two critical characteristics were inspected in a sample of 500 orders. Fifty errors were found on 25 of the orders, but 20 of these orders were reprocessed to correct the errors. The throughput yield is:
a. 90%.
b. 95%.
c. 99%.
d. 97.5%.
9. If the throughput yield is calculated as 85%, then:
a. At any given time, 15% of the units will be defective.
b. At any given time, 85% of the units will be defect-free.
c. On average, 85% of the units will have no defects.
d. Choices a and b.
10. The throughput yield for six departments processing an order in series is as follows: 99.7%, 99.5%, 95%, 89%, 92.3%, and 94%.
The probability of no defects across all steps is:
a. 89%.
b. 73%.
c. 77%.
d. Approximately 30%.
11. Measurement systems analysis is needed because:
a. Measurements by different personnel using the same equipment on the same sample unit can vary.
b. Measurements by the same personnel using the same equipment on the same sample unit can vary.
c. Calibration will not remove all measurement error.
d. All of the above.
12. Residuals are:
a. The error between the actual y value and the predictedy value at eachx value.
b. The difference between the observedxvalue and the regression line in they direction.
c. Due to error.
d. All of the above.
13. In the expression cycle time (in minutes)¼3þ1.4 * (number of orders)2.1 * (number of clerks).034 * (process distance):
PART 2 Exam 171
a. Removing one clerk will increase the cycle time by 2.1 minutes.
b. Adding 5 orders will increase the cycle time by 7 minutes.
c. Removing one clerk and adding five orders will increase the cycle time by about 9 minutes.
d. All of the above.
14. In the interaction plot below, it is evident that:
a. There is a strong interaction between moisture and fill pressure.
b. There is a weak to negligible interaction between moisture and fill pressure.
c. The effect of fill pressure on part density changes drastically as we change the moisture.
d. None of the above.
15. An ANOVA analysis provides the following p values:
Intercept¼0.03 Factor A¼0.73 Factor B¼0.02 Factor C¼0.10
Given this data, we might assume:
a. Of the three factors investigated, factor A is most significant.
b. Of the three factors investigated, factor B is most significant.
c. Of the three factors investigated, factor C is most significant.
d. None of the above.
16. In identifying which processes provide value, a company should first:
a. Evaluate key processes using a cost/benefit analysis.
b. Understand their customers’ processes and needs.
c. Set up a team of internal experts that are familiar with the processes and their design.
d. Benchmark competitors’ products and processes.
17. A company optimizes its processes to complement its strengths in product development. This approach:
a. Will certainly improve the company’s ability to service customers.
b. Will certainly improve the company’s long-term profitability.
c. All of the above.
d. None of the above.
18. In analyzing the value stream, it is observed that a bottleneck occurs in operation 4, which removes excess material from a part prior to the finishing operation. A response to this should be:
a. Operation 4 needs more personnel.
b. The operation that produces the excess material prior to operation 4 should be examined.
c. Personnel from downstream processes should be moved as needed to operation 4 to eliminate the bottleneck.
d. All of the above.
19. Screening designs are often used:
a. To conclusively prove the factors critical to process control.
b. To reduce the list of possible factors influencing a process.
c. To optimize a process.
d. All of the above.
20. We often fold a design:
a. When we can’t run enough conditions in a given day.
b. To produce independent estimation of confounded terms.
c. To reduce the number of runs.
d. All of the above.
PART 2 Exam 173
21. Inadvertent errors can be prevented by:
a. Automation.
b. Foolproofing.
c. Ergonomic design.
d. All of the above.
22. Lack of fit error may be due to:
a. Higher order effects that are not included in the model.
b. Main factors that are not included in the model.
c. Interactions that are not included in the model.
d. All of the above.
23. If we conduct a screening experiment and conclude that lack of fit error is significant:
a. We need to throw out our data and start over.
b. We can add center points (if we don’t have them) and estimate surface curvature.
c. We may want to extend the design to add more main factors or interactions.
d. Both b and c.
24. Process control is most effective:
a. When we concentrate on the process outputs.
b. When we concentrate on the process inputs.
c. When applied as sampling inspection of supplier material.
d. When all process parameters are monitored.
25. When quality improvement plans are implemented, an effective control plan includes training:
a. On the principles driving the change.
b. To ensure the employees understand their role in the problem- solving stage of the new process.
c. For operational employees to acquire the skills necessary to perform the new procedures or tasks.
d. All of the above.