8D (8 Disciplines) 8 Steps to Problem Solving
The original name of 8D is 8 Disciplines, which means 8 fixed steps that everyone knows to solve a problem. Originally, it was a special and necessary method for global quality control and improvement by Ford Company, and later it has become a special requirement of QS9000/ ISO TS16949, Ford Company. For all parts of FORD, 8D must be used as a tool for quality improvement. At present, some companies are not suppliers of FORD or partners of the automotive industry. They also like to use this convenient and effective method to solve quality problems. It has become a fixed and consensus. standardized problem-solving steps.
Discipline 1. Form the Team: It is composed of people related to the issue, usually cross-functional, and explains the division of labor or the responsibilities and roles of team members.
Discipline 2. Describe the Problem: Quantify and express the problem as clearly as possible, and solve medium and long-term problems rather than immediate problems.
Discipline 3. Implement and confirm temporary countermeasures (Contain the Problem): Immediate and short-term actions to solve D2, to avoid the expansion or continuous deterioration of the problem, including clearing inventory, shortening PM time, and dispatching manpower, etc.
Discipline 4. Identify the Root Cause: The real cause of the D2 problem, the analysis method, and the application of tools (quality tools).
Discipline 5. Formulate and Verify Corrective Actions: Formulate improvement plans, list possible solutions, select and implement long-term countermeasures, verify improvement measures, and eliminate the real cause of D4, usually with a A step-by-step approach explains long-term improvement strategies, can apply project planning Gantt Chart (Gantt Chart), and illustrates the application of quality methods.
Discipline 6. Correct the Problem and Confirm the Effects: Verification of results and effects after performing D5.
Discipline 7. Prevent the Problem: Follow-up action plan to ensure that the D4 problem will not recur, such as personnel education and training, improvement case sharing (Fan out), work standardization, BKM output, ECN implementation, sharing knowledge and experience, etc.
Discipline 8. Congratulate the team and plan the future direction (Congratulate the Team): If the problem has been improved after the above steps are completed, it will definitely improve the team's efforts and plan the future direction of improvement.
8D scope of application
This method is suitable for solving all kinds of simple or complex problems that may be encountered;
The 8D approach is all about building a system where the entire team can share information and work toward goals.
8D itself does not provide a method or approach to successful problem solving, but it is a useful tool for problem solving;
It is also applicable to the solution of relevant problems when the process capability index is lower than its due value;
In the face of customer complaints and major defects, provide solutions to the problem.
The 8D method is a method used by Ford in the United States to solve product quality problems. It has been widely implemented among suppliers and has now become the best and most effective method for solving product quality problems in the international auto industry (especially auto parts manufacturers). Methods.
8 steps of the 8D working method
8D is 8 basic principles or 8 working steps for problem solving, but in practice there are 9 steps:
D0: Symptom emergency response
D1: Group Formation
D2: Problem statement
D3: Implement and verify interim measures
D4: Identify and verify root cause
D5: Select and Validate Permanent Corrective Actions
D6: Implement Permanent Corrective Actions
D7: Prevent recurrence
D8: Group congratulations
D0: Symptom emergency response
Purpose: It is mainly to see whether such problems need to be solved by 8D. If the problem is too small, or it is not suitable to be solved by 8D, such as price, funding, etc., this step is for emergency response when the problem occurs.
Key Takeaways: Determine the type, size, scope, etc. of the problem. Unlike D3, D0 is a reaction to the occurrence of a problem, while D3 is a temporary response to the product or service problem itself.
D1: Group Formation
Purpose: To establish a team with process/product knowledge, allotted time and authority, and the required technical quality to solve problems and implement corrective actions. The group must have a mentor and group leader.
Key points: membership, knowledge of process, product; goals; division of labor; procedures; team building
D2: Problem statement
Purpose: To specify in quantitative terms the internal/external customer complaints related to the problem, such as what, where, when, how much, how often, etc.
"what went wrong"
Methods: Quality Risk Assessment, FMEA Analysis, 5W3H
Key Takeaways: Gather and organize all relevant data to illustrate the problem; a problem statement is a summary of particularly useful data for the problem described; review existing data to identify and scope problems; subdivide problems to break down complex problems into individual problems ;Problem definition, find a description that is consistent with the problem identified by the customer, "what went wrong", and the cause is unknown risk level.
D3: Implement and verify interim measures
Purpose: To ensure that problems are isolated from internal and external customers until permanent corrective action is implemented. (Originally the only optional step, but it has been used until now)
Methods: FMEA, DOE, PPM
Key Takeaways: Evaluate emergency response; identify and select optimal "interim containment measures"; make decisions; implement, and document; validation (DOE, PPM analysis, control charts, etc.)
D4: Identify and verify root cause
Purpose: Use statistical tools to list all potential causes that can be used to explain the cause of the problem, test in isolation from each other a series of events or circumstances or causes of deviation mentioned in the problem statement, and determine the root cause of the problem.
Method: FMEA, PPM, DOE, Control Chart, 5why method
Key Takeaways: Evaluate each cause in the list of possible causes; whether the cause can be ruled out; verification; control plan
D5: Select and verify permanent corrective actions
Purpose: To test the protocol before production and review the protocol to determine that the corrective actions selected will solve the customer problem without adversely affecting other processes.
Method: FMEA
Key Takeaways: Revisit team membership; decision-making, select best course of action; re-evaluate interim measures and re-select if necessary; verification; management commitment to permanent corrective action; control plan
D6: Implement Permanent Corrective Actions
Purpose: Develop a plan to implement permanent measures, identify and document process control methods to ensure root cause elimination. The long-term effect of this measure should be monitored when it is applied in production.
Methods: error proofing, statistical control
Key Takeaways: Revisit team members; implement permanent corrective actions, repeal temporary actions; use fault measurability to confirm fault has been eliminated; control plan, process documentation revisions
D7: Prevent recurrence
Purpose: To modify existing management systems, operating systems, work practices, designs and procedures to prevent the recurrence of this problem and all similar problems.
Key takeaways: selection of preventive measures; verification of effectiveness; decision making; organization, personnel, equipment, environment, materials, documentation redefine
D8: Group congratulations
Purpose: To acknowledge the collective effort of the group, summarize and congratulate the group work.
Key points: Selectively retain important documents; browse the work of the group and document the experience; understand the collective power of the group to solve problems and their contribution to solving problems; necessary material and spiritual rewards.
8D application
Supplier A manufactures plastic products for customer B. According to the customer's plastic product appearance standards, on May 29, 2007, they received a shrinking complaint from customer B's factory: the appearance of plastic products does not meet the standard.
No matter how the question is asked or from whom, Company A will respond with an 8D process. To encourage good contact between supplier and customer, B should assist supplier A to respond quickly to any problems within 24 hours. Ideally, A sends a representative to Factory B to review the problem and help determine the root cause of the problem. If A is unable to send a representative to B's factory, A should request B to ship back the defective parts immediately so that A can help solve the problem. Waiting for a response to a problem will have a negative impact on the customer. The longer the wait for a response, the more difficult it will be for the supplier to solve the problem. A positive attitude and willingness to help each other can make the process proceed quickly and smoothly.
D-1 Team Member
Form groups and appoint leaders. Team members consist of production engineers and quality engineers with relevant technical knowledge to avoid having only one or two people implementing the process.
D-2 Question Details
Basically, there are three kinds of problems a part can have: A problem, a design problem, and a B problem. If A confirms that it is A's problem, A should immediately start the containment step of the 8D process; if it is a design problem, A should still start the 8D process, formally documenting that the cause is the design problem; if A believes it is B's problem and not A's problem, A should still start the 8D process to help B validate the problem, after supporting B's confirmation of the problem in the form of documents and 8D reports, A can hand over, although the situation may be difficult to resolve quickly, but A handles it in a proactive manner Problems Helping B solve the problem will help the problem to be improved quickly and easily and have a better working relationship with B.
Common mistakes
Common mistakes that occur at this step: working on symptoms rather than the real problem; premature assumptions about the root cause of the problem; revising the customer's description of the problem as his own, which is often just a symptom of the problem rather than the real problem.
quality tools
Arrangement diagrams, flowcharts, cause and effect diagrams.
After receiving complaints from customers, Company A immediately launched an investigation. After inspecting the samples, the conclusion was the same as that of the customers. The confirmed problems were as follows: All samples were confirmed by the team members, and a total of 500K products were shipped to Factory B. Among them, it was found that there were 17 pieces of reduced model, and the remaining 208K.
D-3 Immediate Countermeasures and Problem Confirmation
D-3.1 Immediate Countermeasures and Problem Confirmation
1. Print the picture of the defect in the reduced mold to inform all production operators, quality inspectors, and selectors to pay attention to checking this problem.
2. Notify the injection molding department to check whether the current production products have this problem, train and educate all injection molding department operators and selectors to let them know that the most important thing is to abide by the work procedures and instructions to maintain the quality of the customer's products and make them aware Their important responsibility in product quality assurance, emphasizing that any mistakes caused by carelessness are not allowed and cannot be repeated, because it will bring unnecessary losses to customers. Therefore, it is necessary to educate employees by showing the mistakes that cost customers.
3. Set up a customer complaint handling team to find the real reason and solve it.
D-3.2 Inventory Handling
1. 100% selection of all warehouse finished products, the total number is 128k, and 5 products are found to have the same problem, and the selected qualified products will be labeled with OK labels on the inner and outer packaging;
2. Arrange replacement processing for customer inventory 208k.
Common mistakes
Common mistakes that occur at this step: Review of screening material is an unsatisfactory containment measure; inventory at all suspect locations is not cleared and nonconforming product is re-entered into the production cycle.
quality tools
Paretograms, statistical process control, failure and failure mode analysis.
D-4 Analysis and Confirmation of Bad Reasons
D-4.1 Analysis of bad causes: During the production process, if any abnormality occurs, the injection molding machine will monitor and alarm. After the alarm is processed, the first few molds produced may have shrinkage.
D-4.2 Defect cause confirmation: 15 alarms were counted throughout the day on May 31, a total of 13 times. Among the first 3 mold products produced after the alarm, 17 molds were found, and the defect rate was 17 cases/(13 times * each The production cycle can produce 12 pieces) = 10.9%, according to the quantity of 1 day, the defect rate is about: 17 pieces / 1 day's output 1036800﹦0.018%) Confirm that in this case, if it is handled improperly, it will indeed cause the shrinkage to be mixed into the good product.
D-4.3 Analysis of the reasons for the outflow of defective products:
After the alarm processing, the first few mold products produced were not completely isolated and mixed into the good products.
D-4.4 Reason for outflow: Due to the small proportion of defective products, the quality inspector did not find it during random inspection.
Common mistakes
Common errors that occur at this step: The stated root cause is not the real root cause, the operator mistakenly prepared the problem you or a symptom or result of the problem is given as the root cause.
quality tools
Cause-and-effect diagrams, failure and failure mode analysis, whether analysis, experimental design, robust design.
D-5 Defective causes and countermeasures
D-5.1 Improvement countermeasures for bad causes:
1. Formulate operating specifications for this series of products, requiring operators to ensure separation of defective products when alarming.
2. Improve the receiving device, from before the improvement: the product is directly ejected from the mold and then falls into the hopper. After improvement: The manipulator is equipped with suction cups to absorb the product, and then put it into the good product box. After the alarm is turned on and the automatic is turned on again, the first 5 molds are automatically put into the material rod entrance, so as to ensure that the shrink-molded products will not enter the good product box.
D-5.2 Outflow Cause Improvement Countermeasures: The operator ensures that the defective products are separated when the alarm is issued.
Quality Tools: Cause and Effect Diagrams, Failure and Failure Mode Analysis, Design Verification and Reporting, Robust Design.
D-6 Determine the improvement actions to be implemented
1. The product has been improved on a pilot injection molding machine, and will be extended to all series products after confirmation.
2. Quality inspectors conduct regular audits as audit items.
3. Arrange operators to select 100% of the products within one week after the implementation of the improvement measures to verify the effectiveness of the measures, and the defect rate after improvement is 0.
For the above work, the team members jointly carried out the verification, and asked the customer to approve it in advance.
Quality Tools: Failure and Failure Mode Analysis, Whether Analysis, Statistical Process Control.
D-7 Preventive measures for similar product or process problems
The product range of the Code of Practice includes products similar to this product.
Common mistakes
Common mistakes in this step: Does the precautionary measure include a separate review process?
quality tools
Control plans, failure and failure mode analysis, process flow diagrams.
D-8 Group and member achievement recognition
The improvement action is valid and can be completed; if the improvement action is invalid, the improvement action needs to be repeated. If the technical engineer of A needs to improve the imperfect 8D, he can use the following ways: Recommend and recommend based on reliable knowledge of the 8D process to demonstrate the quality tool knowledge of the steps of the process and the purpose of each step, provide on the basis of real evidence Open, mutual critique; emphasizes the importance of 8D process training, training about the 8D process, continuous 8D process reflects their overall quality system is complete or not; encourages a prevention-oriented philosophy, using prevention as a way to complete the 8D process the ultimate goal.
Before B asks A to attend the meeting and provide up-to-date documentation of the concern, A technical engineer provides sufficient supporting documentation for 8D process improvement, digitized pictures, failure and failure mode analysis, control plan and any other documentation that needs to be updated; convenes manufacturing Team members of the process meet to review; review all information and documents prior to the meeting and ensure that it has been obtained and sufficient, and have knowledge of the event; if available and required, consult the client to determine the focus of the meeting and better Prepare.