6Sigma六西格玛精益生产持续改善分析管理常用工具资料 The_Lean_Enterprise_22_8D_approach(8D方法)

1、Improvement Initiatives presents TEAM-ORIENTED PROBLEM SOLVINGA SYSTEMATIC PROBLEM SOLVING PROCESS 8-D1Problems take longer to solve than to prevent.If theres no time to do it right the first time, you will have to find the time to do it overand over.and over.USE THE 8-D PROBLEM SOLVING DISCIPLINE O

2、NLY WHEN THE CAUSE IS UNKNOWNIf you dont know why a problem happened, all your corrective actions are guesses, not fixes.85% of problem are system oriented. Only 15% are local causes. Knowledge of the entire system is essential.2Problem solving problems:Problem is described incorrectly or inadequate

3、lySome of the 8-D steps are skipped or sluffed offPoor team make up or poor participationLack of team technical expertise and skillsIncorrect or incomplete root cause was identifiedPreconceived notions clouded the problem solving process3The ChosenMany problem solving methods exist:Ford typically us

4、es a method called 8DGM typically uses a method called 5PChrysler typically uses a method called 7DMany companies use a 4SWe have chosen to use the 8D process as it incorporates the other methods4.Document a procedure for problem solving5The 8D process consists of 8 specific problem solving discipli

5、nes. D1. USE TEAM APPROACH D2. DESCRIBE THE PROBLEM D3. IMPLEMENT AND VERIFY INTERIM (CONTAINMENT) ACTIONS D4. DEFINE AND VERIFY ROOT CAUSES D5. VERIFY CORRECTIVE ACTIONS D6. IMPLEMENT PERMANENT CORRECTIVE ACTIONS D7. PREVENT RECURRENCE D8. CONGRATULATE YOUR TEAMThe initial event is that you BECOME

6、AWARE OF A PROBLEMYou can ignore it - and it will bite you again even harderOr you can begin the process to eliminate its cause6D1. USE TEAM APPROACH Establish a small group of people with the: process/product knowledge, allocated time, authority, and skill in the required technical disciplines to s

7、olve the problem and implement corrective actions. The group must have an actively interested designated champion. D2. DESCRIBE THE PROBLEMSpecify the internal/external customer problem by identifying in quantifiable terms the who, what, when, where, why, how, how many (5W2H) for the problem.D3. IMP

8、LEMENT AND VERIFY INTERIM (CONTAINMENT) ACTIONSDefine and implement containment actions to isolate the effect of problem from any internal / external customer until corrective action is implemented. Verify the effectiveness of the containment action.D4. DEFINE AND VERIFY ROOT CAUSESIdentify all pote

9、ntial causes which could explain why the problem occurred. Isolate and verify the root cause by testing each potential cause against the problem description and test data. Identify alternative corrective actions to eliminate root cause.D5. VERIFY CORRECTIVE ACTIONSThrough pre-production test program

10、s quantitatively confirm that the selected corrective actions will resolve the problem for the customer, and will not cause undesirable side effects. Define contingency actions, if necessary, based on risk assessment.D6. IMPLEMENT PERMANENT CORRECTIVE ACTIONS Define and implement the best permanent

11、corrective actions. Choose on-going controls to ensure the root cause is eliminated. Once in production, monitor the long-term effects and implement contingency actions, if necessary.D7. PREVENT RECURRENCEModify the management systems, operating systems, practices, and procedures to prevent recurren

12、ce of this and all similar problems.D8. CONGRATULATE YOUR TEAMRecognize the collective efforts of the team.7DISCIPLINE #1 - (D1)Team members must be:Willing to contributeCapable of intelligently diagnosing problemsTrainable - willing to learn:New improvement methodsFrom each otherNew problem solving

13、 methodsTeam playersTrusting team membersWilling to do their part, bringing their expertise and skills to bear on the problemBasic team principles Focus on the situation issue or behavior, not other persons Maintain the self-confidence and self-esteem of others Maintain constructive relationships wi

14、th your team members and support personnel Take initiative to make things better Lead by exampleGood team members will Encourage and be spontaneous Accept and give consideration off the wall ideas and out of the box thinking and suggestions- Overcome preconceived notions- Never reject a possibility

15、just because we looked at that last year De-emphasize rank Not engage in brown nosing or power pushing8DISCIPLINE #2 - (D2)Define the problem specifically and clearly Determine the extent of the problem Narrow the focus of the problem solving Summarize ALL the known FACTSIn defining the problem:Trut

16、h is separated from fictionOpinion is separated from factEmotion is separated from realityFrequently the wrong problem is solved and the issue that caused the customer complaint is not addressed. It is imperative the customer complaint be clearly understood. The only method to ensure this is to have

17、 direct customer contact. It is not unusual for a complaint to be misrepresented by someone who is reporting it rather than experiencing it. Reporting systems and tally sheets are often used that mis-classify problems in prearranged but incorrect standard categories.Part of the 5W2H problem definiti

18、on is to state the customer complaint clearly and accurately.95W2HHELPS CHARACTERIZE THE PROBLEM FOR FURTHER ANALYSIS.WHO. Identify individuals associated with the problem. Characterize customers who are complaining. Who is having difficulty?WHAT. Describe the problem adequately. Does the severity o

19、f the problem vary? Are operational definitions clear (e.g., defects)? Is the measurement system repeatable and accurate?WHERE. If a defect occurs on a part, where is the defect located? What is the geographic distribution of customer complaints? Where the difficulties being detected?WHEN. Identify

20、the time the problem started and its prevalence in earlier time periods. Do all production shifts experience the same frequencies of the problem? What time of the year does the problem occur?WHY. Any known explanation contributing to the problem should be stated.HOW. In what mode of operation did th

21、e problem occur? What procedures were used?HOW MANY. What is the extent of the problem? Is the process in statistical control? (e.g., P chart)10In addition to the 5W2H analysis, it is often useful to identify:What the problem IS - and - What the problem IS NOTA PROBLEM SOLVING WORKSHEET THAT COMBINE

22、S 5W2H AND IS/IS NOT ANALYSIS CAN BE A GOOD TOOL TO ENSURE ALL ASPECTS OF DEFINING THE PROBLEM HAVE BEEN CONSIDERED11WHO, WHAT, WHEN, WHERE, WHY, HOW, HOW MANY:1. What is the magnitude of the problem?2. Has the problem been increasing, decreasing, or remaining constant?3. Is the process stable?4. Wh

23、at indicators are available to quantify the problem?5. Can you determine the severity of the problem? Can you determine the various costs of the problem? Can you express the cost in percentages, dollars, pieces, etc.?6. Do we have the physical evidence on the problem in hand?7. Have all sources of p

24、roblem indicators been used?8. Have failed parts been analyzed in detail?9. Is there an action plan to collect additional information?CUSTOMER TERMS/SYMPTOMS:1. Who is the customer?2. What customer first observed the defect?3. To whom was it reported?4. What is the problem definition in customer ter

25、ms?5. What is the problem definition in our terms?6. Have we verified the problem with on-site visits with the customer? Have we seen it for ourselves?5W2H Questions12DISCIPLINE #3 - (D3)Isolate the customer from reoccurrences of the problem Immediate gathering, quarantine, and lock-up of all suspec

26、t product Stop production from known problem sources / contributors Examine DATA - FACTUAL EVIDENCE to help determine what to contain and who to stop Verify by experimentation and data tracking and collection that the problem has been containedCONTAINMENT ACTIONS ARE NOT AND NEVER SHOULD BE CONSIDER

27、ED PERMANENT SOLUTIONS TO A PROBLEM.13D3-IMPLEMENT INTERIM (CONTAINMENT) ACTIONSOBJECTIVE: Define and implement containment actions to isolate the effect of the problem from any internal or external customer until corrective action is implemented. Verify the effectiveness of the containment actions.

28、 State all containment actions and when they will be implemented. Perform tests to evaluate the effectiveness. State the results. State the procedures for on-going evaluation of the effectiveness (e.g., control charts, check sheets, etc.). Coordinate an action plan for implementing interim actions.

29、The search for root cause should proceed concurrently with the implementation of containment actions.ASSESSING QUESTIONS: You are prepared for a review when you can answer these questions:VERIFICATION1. Have all alternative actions been evaluated?2. Are responsibilities for correct actions clear?3.

30、Is the required support available?4. When will the actions be completed?5. Does the containment action protect the customer from the effects of the problem?CONTAINMENT ACTIONS1. What containment actions have been identified?2. Have you ensured that implementation of the interim solution will not cre

31、ate other problems?3. Will all interim actions last until long-range actions can be implemented?4. Have you coordinated the action plan with the customer?CONFIRMATION ACTIONS1. Have tests been done to evaluate the effectiveness of the interim actions?2. Can you conduct controlled experiments to pred

32、ict the outcome of the actions?3. Can you try out the actions on a small scale to test if they will be effective?4. Is data being collected to ensure actions will remain effective?14COLLECT AND ANALYZE DATA Collect data to determine importance of potential causes. Several potential causes may need t

33、o be analyzed through data. Six steps in investigating a potential cause1) How could the potential cause have resulted in the problem?2) What type of data should be collected to prove it?3) Prepare the materials to conduct the study4) Collect the data5) Analyze statistically6) State conclusions15COL

34、LECT AND ANALYZE DATA TO DETERMINE IF A POTENTIAL CAUSE IS A ROOT CAUSEAfter cause-and-effect diagrams have been completed, data needs to be collected to determine which potential causes are important. Pareto diagrams and check sheets are very effective in establishing the importance of the potentia

35、l causes.It is a mistaken belief that data oriented problem solving can be accomplished by collecting relevant data on a problem, analyzing the results, and deciding the correct solution. Once data is collected and analyzed, new questions often arise, so another data collection and analysis iteratio

36、n is necessary. Many problems can have more than one root cause. Data collected investigating one potential cause may not address other important potential causes. Several potential causes may need to be studied using the data collection and analysis process.Once a potential cause has been selected

37、for investigation, the following steps are required: State how the potential cause could have resulted in the described problem. Establish what type of data can most easily prove or disprove the potential cause. Develop a plan on how the study will be conducted. Identify the actions on an action pla

38、n. Organize and prepare the required materials to conduct the study. Collect the required data. Use appropriate statistical tools emphasizing graphical illustrations of the data. Outline conclusions from the study. Does the data establish the potential cause as being the reason for the problem or do

39、es the data point to another potential cause that needs to be investigated also?Data collection may be as simple as check sheets or as sophisticated as design of experiments. By using graphical tools, quick comprehension by all participants as well as accurately communicated information will result.

40、 16DISCIPLINE #4 - (D4) DEFINE AND VERIFY ROOT CAUSESOnce you have satisfied yourself you have identified the root cause(s), retest and verify all data pointing to the suspected root cause(s) - Make the problem come and go!The important thing here is to be sure you have Identified and tested ALL pot

41、ential causes17D4 - DEFINE AND VERIFY ROOT CAUSESOBJECTIVE:Identify all potential causes which could explain why this problem occurred. Isolate and verify the root cause by testing each potential cause against the problem description and test data. Identify alternative corrective actions to eliminat

42、e root causes.Identify Potential Causes Define the effects for a Cause-&-Effect diagram clearly. Prepare a 5M, Process, or Stratification Cause-&-Effect diagram for each effect. You may choose to use a combination. Team members should each assume their activity causes the problem.Each should ask the

43、mselves How could what I do possibly generate the problem?. Prepare a Time Line Analysis if the problem was not always present. Identify what changed, when? Perform a Comparative Analysis to determine if the same or a similar problem existed in related products or processes. Identify past solutions

44、and root causes which may be appropriate for the current problem.Check the Lessons Learned data and similar product DFMEA / PFMEAs Identify several potential causes. Develop a plan for investigating each cause, and update the Action Plan. Evaluate a potential cause against the problem description.18

45、Problem Solving Tools - Root cause identification and verificationFlow ChartingCause and Effect DiagramsScatter DiagramsHistogramsCheck SheetsPareto ChartsRun ChartsControl ChartsBrainstormingProblem Solving Techniques Use brainstorming and Cause and Effect diagrams to narrow potential root causes C

46、ompare selected potential root causes to the IS/IS NOT data Investigate several root causes at the same time Conduct experiments to verify your selected root cause(s) Do a DOE - Taguchi Study if necessary Ask for additional help if necessaryD4 - DEFINE AND VERIFY ROOT CAUSESAnalyze Potential Causes

47、Use the iterative process to analyze each potential cause: Hypothesis Generation: How does the potential cause result in the problem? Design: What type of data can most easily prove or disprove the hypothesis? Preparation: Obtain materials and prepare a check sheet. Data Collection: Collect the data

48、. Analysis: Use simple, graphical methods to display data. Interpretation: Is the hypothesis true?Investigate several potential causes independently.Use an Action Plan to manage the analysis process for each potential cause being studied.1920CAUSE AND EFECT DIAGRAMSONCE A CLEAR AND SPECIFIC PROBLEM

49、IDENTIFICATION HAS BEEN MADE, A CAUSE AND EFFECT ANALYSIS SHOULD BE COMPLETED.Cause and Effect Diagrams are graphic representations of potential problem causes. They are sometimes called:FISHBONE DIAGRAMS, ISHIKAWA DIAGRAMS or CAUSE AND EFFECT DIAGRAMSThere are various types of cause and effect diag

50、rams including:PROCESS FLOW, 5M (sometimes called 5M and E), STRATIFICATIONThe type C&E diagram utilized should be the one (or more) that provides the best detailed breakdown of potential causes.Ask yourself: What variability could result in the stated problem?” Add each identified potential source

51、of variation to the C&E diagramWithout variability, either there are No problems (all good) or Everythings a problem (all bad)With variability, there are probably Some good and some bad.Continue to ask the question for each main branch of the Cause-and-Effect diagram.The Objective is to Identify all

52、 potential causes of the problem (by identifying sources of variability).21D4 - DEFINE AND VERIFY ROOT CAUSESValidate Root Causes Clearly state root cause(s) and identify data which suggests a conclusion. Verify root cause factors are present in the product or process. Can we generate the problem in

53、dependently? Can we make it come and go?VERIFY YOUR ROOT CAUSE CANDIDATES - Make the problem come and go - Turn it on and off -22D4 - ASSESSING QUESTIONS:POTENTIAL CAUSES:1. Have you drawn the process flow and stratification C&E diagrams and identified all sources of variation?2. Have all sources of

54、 information been used to define the cause of the problem?3. Do you have the physical evidence of the problem?4. Can you establish a relationship between the problem and the process?5. Do you continually challenge the potential root causes with the question why then follow with because to construct

55、alternative potential causes?6. Is this a unique situation or is the likely problem similar to past experience?7. What are the is, is not differences?8. Has a comparative analysis been completed to determine if the same or similar problem existed in related products?9. What are the experiences of re

56、cent actions that may be related to this problem?10. Why might this have occurred?11. Why havent we experienced this before?12. What changed?Manufacturing:Engineering:- new suppliers?- any pattern to the problem? - new tools?- geographically?- new operators?- time of year?- process changes? - build

57、dates?- measurement system?- did the problem exist at program sign-off?- raw materials?- was it conditionally signed-off?- vendor-supplied parts?- did the problem exist on prototype vehicles? - do other plants have a similar problem?- did the problem exist on the functional builds?- did the problem

58、exist on the 4-ps? (pre-production product prove-out)23D4 - ASSESSING QUESTIONS:DATA:1. What data is available to indicate any changes in the process?2. Does data exist to document the customers problem?ROOT CAUSE1. If the potential cause is the root cause, then how does it explain all we know about

59、 the problem? How has this been verified?2. Is there any possibility that there is another contributing cause besides the one we have identified? How is this being evaluated?OTHER POTENTIAL CAUSES1. What evidence do you have that other potential causes are actually occurring?2. If they are occurring

60、, what unwanted effects might they produce?3. Do actions need to be taken to ensure that other potential causes do not create unwanted effects?24DISCIPLINE #5 - (D5)To this point we have focused on: Understanding and defining the problem Containing the effects of the problem Identifying and Verifyin