8D is an 8-step problem-solving methodology (“Disciplines”).
The Ford company, in 19871, faced recurring problems, which documented this methodology in a handbook entitled “ Team Oriented problem Solving “2. Originally called “8 disciplines“, or “Global 8D” (G8D), it was used by the U.S. Army during the Second World War as military standard 1520 (corrective action and disposition system for non Compliant). Subsequently, Ford management took over this method to solve problems3.
The method is based on the fact that a good problem solving is the result of the work of a multidisciplinary team. Two stages are dedicated to the team: the first on the composition of this one and the last to congratulate4.
By making a beautiful part of the team, the method allows in particular to:
- Increase team involvement in problem solving.
- Increase the number of solution idea to the problems.
- To bring more knowledge and expertise to find the best causes.
Beyond that, it allows structuring the approach to increase the responsiveness of response to problems with the customers. As well:
- At Ford, a supplier must be able to respond from step 6 of the process within 15 days5
- At Faurecia, a supplier must respond within 24 hours of step 3, 10 days for step 6, and 60 days to close project6
1. Set up the team
The 8d methodology is based on the team. This first step is paramount and sees the formation of a coherent multidisciplinary team:
- 1 Pilot: Responsible for the group and methodology.
- 5 to 8 people from various services: production, purchase, customer, technical expert…
- The minimum presence of an operator.
- All participants must be concerned with the problem.
- A knowledge of the Gemba is necessary.
- All must have time and authority to work to solve problems.
The 2 rules of the team 8D
The team will have to demonstrate during the project of availability and envy to participate in the project.
The pilot is responsible for the application of the principles of the state of mind Genchi Genbutsu.
2. Describe the problem
The challenge of the stage is to formulate the problem in clear, precise and quantifiable terms. In the first place, a few samples or all the elements/parts representative of the problem must be obtained.
Then we use the 5W2H, draw a drawing and take pictures.
Once the problem is clearly identified, we must:
- Reproduce the problem: best way to make sure we understand it
- Set up a FMECA To identify and prioritize the problem.
3. Set up Conservatory actions
It is a question of isolating the effects of the problem in order to correct it without harming the customer or the production, while waiting for definitive actions to be put in place. For this, we must:
- Define the list of the products incriminated via the traceability of the lots
- Define the potentially problematic processes that cause the problem
- Carry out a FMECA to prevent the risks associated with the implementation of these actions
- Ensure that conservatory actions eliminate at 100% the risk of detection of the problem by the customer as well as its dissemination on other products or processes
- Trace the entire value chain to identify where there may be parts (from vendor to customer).
These conservatory actions may be:
- Sorting in stocks (final, in-progress…) and if necessary in the customer stock or at the supplier.
- The setting up of self-control.
- Visual aids.
- The setting up of Poka-Yoké.
- The 100% control of the parts.
- If necessary, the cessation of production may be considered.
4. Identify and verify root causes
8d relies on various tools to identify the root cause:
- Simple tools such as the 5 why, the cause/Effect diagram, Pareto analysis, Process Map.
- More complex analysis tools such as Factor Tree analysis, PM analysis, Design Of Experiment.
- Basic Tools for statistical analysis: Regression and control chart.
5. Identify and verify corrective actions
Having acquired knowledge, the composition of the team is validated by checking whether it is relevant to the subject to be dealt with.
We brainstorm on causes to identify possible solutions based on the tools of creativity. Then, the corrective actions are selected by:
- Checking their expected effect on the problem.
- Checking that they have no adverse effect.
- Prioritizing them via the gain/cost matrix
On the other hand, we must ensure that the precautionary actions put before are still active and isolate the problem well.
6. Set up corrective actions
We’re going to put in place the corrective actions we’ve identified. Once the implementation is completed, audits are carried out:
- Set up actions to correct non-detections.
- Measure the results obtained from the indicators defined at the beginning of the project.
- Check the quality of the actions by performing in hypothesis testing.
- If the problem is completely eliminated, stop the precautionary actions put before.
- If the results are not conclusive, resume from step 2.
7. Preventing recurrence
Preventing recurrence is a key step in an 8d. This is to follow up on the corrective actions over the duration:
- Put under control the process (SPC, FMECA…)
- Validate that the effects of the problem are part of a customer request
- Validate that the actions have no negative effects.
- Are the corrective actions confirmed by indicators?
- Is fault detection effective?
- Have there been any recurrences?
- Are all operators trained?
- Technical follow-up of corrective action to ensure proper functioning
Finally, if all the preceding points, the corrective actions are deployed:
- Edit All Documentation: instructions, standards…
- Generalizing actions on similar products, machines or processes
- Develop the lessons learned
- Inform and train all impacted staff
8. Congratulate the team
The closure of 8d is done by the management’s congratulations to the operational teams. This can be done via:
- A closing meeting in the presence of the management
- Individual letter
- Thank the team during a ” classic ” meeting
1 – J. C. Massé (2010) – Collective sports problem solving process
2 – Ford (1989) – Team oriented problem solving process
3-L. Avrillon (2005) – Quality problem solving process in the context of new high-tech products
4-A. M. Chaudhry (1999) – To be a problem solver, be a classicist
5 – Ford Motor Company (2013) – Customer specific requirements
6 – Faurecia (2012) – Supplier Requirements Manual
L. R. Marchini (2013) – Disciplina 8d
E. E. Broday, P. P. Andrade (2013) – Application of Quality management tool for solving industrial problems
L. Rambaud (2006)-structured resolution of problems 8d: A guide to creating high quality 8d reports.