8D is a problem solving method used globally, mainly in manufacturing industry by Quality Engineers and Operations managers. The purpose of 8D problem solving method is to identify, correct and prevent problems affecting customers and operational efficiency. It is a problem solving approach similar to PDCA cycle (Plan – Do – Check – Act).
8D stands for 8 Disciplines. It is a methodology that emphasizes “No problem should be repeated but fixed permanently”.
8D Problem Solving Method originally evolved during Second World War. But it became an official methodology in 1974, when it was used by US Government for its Military Operations as ‘Military Standard 1520’. Later it was adapted and popularized by Ford Motors with slight modification in the methodology.
As the name indicates 8D has 8 disciplines that any process or operations should follow to solve the problems occurring. The outcome of 8D is a report called ‘8D Report’ that records the problems, root cause(s) and corrective and preventive actions.
The below are the D’s in 8D approach:
Figure 1: 8D Problem Solving Approach
1D – Team Formation:
The first and foremost step not only in 8D but also in any other initiative or project is Team Formation, for any initiative cannot be successful without a right team. The team selected should be committed, competent, co-ordinated, cross-functional with representation from all teams, and should be knowledgeable in 8D methodology.
2D – Problem Description:
After selecting the team, our concentration should be on detailing the problem. The team should collect details about the problem, for completely understanding the depth of the problem. All details should be data and fact based.
3D – Interim Containment Actions:
Once the problem is described, before heading up to problem solving, the team should fix the effect of the problem, especially on customers. It might involve actions like isolating the items affected, replacing defective parts, before it reaches the customers. This step is mainly to prevent the problem from reaching the market and customers, which might become a competitive disadvantage and reduce customer loyalty.
4D – Root Cause Analysis:
After taking containment actions, the team should involve in identifying the root cause(s) for the problem. Methods and tools like 5-Why Analysis, Fishbone diagram, Pareto Analysis, 7 Old QC tools, New QC tools etc. can be used for identifying the root cause. An important point to be noted is: Whatever method is used for RCA, it should be data & fact based.
5D – Formulate Corrective Actions:
After successfully arriving at the root cause, the team should formulate corrective actions to be taken to correct the problem. Tools like Brain storming, Affinity diagram etc. can be used.
6D – Validate Corrective Actions:
After arriving at the corrective actions, the team should validate whether the solutions are effective. There are several tools like Accelerated life testing, simulation etc. available for this purpose. Then the solution can be implemented in the process. The solution approach from step 4-6 should be repeated until the problem is completely eliminated.
7D – Preventive Action:
Identifying and implementing corrective actions is only a temporary solution that keeps the system running or is like ‘Living with the problem by taking counter measures’. The permanent solution is to identify a potential long term solution that will not allow the problem (similar problems) from occurring into the system again. Sometimes corrective action will be a costly, time being measure. Preventive action makes changes in the system, upstream or downstream processes so that the entire system is modified or aligned for ‘Problem Free’ operations.
8D – Team and Individual Recognition:
Once the problem is completely solved, the team and the extra-ordinary contributors must be rewarded and recognized appropriately. This will act as a motivation factor for other employees.
These are the steps of 8D methodology. To summarize, 8D is a holistic, systematic and proven methodology for problem solving.