We find thousands of reasons not to implement corrective actions when conducting 8D analysis. The most common explanation is that defective products are no longer sent to customers and we know exactly where the mistake was made.
Often, the condition determining the suspension of the implementation of the above activities are related to costs that would be too high. This means that additional control is maintained at the organization production plant or at the customer’s location.
One of the most important things to remember during analysis performing is to define PCA (Permanent Corrective Actions) that will remove root causes, but without causing another issues. It is also important that the action refers to root causes, and not to the symptoms for which are dedicated Interim Containment Actions – ICA.
Permanent Corrective Actions effectiveness verification
Actions defining which will ensure that we are able to avoid reoccurrence is just part of the 8D methodology process. The next step is to check in practice whether the actions taken bring the intended effect. The key to conducting the assessment is choosing appropriate indicators that will confirm the short and long-term effectiveness of solutions (e.g. ppm). During solution implementation, it should also be observed whether there are no side effects. What does this mean in practice? We are talking about a situation when another type of problem occurs through an action that has not been taken into account when carrying out the risk analysis (for example PFMEA).
If we are considering an official notification from a client, we must remember that a positively validated solution must be accepted by him. Most often this is done by approving the overall 8D report, which is placed on a specific portal used to manage complaints.
The most important, from the production plant point of view, is the fact that validated definitive actions should allow the elimination of temporary actions. Thanks to this, can be eliminated the costs of selection, additional control, using of one machining production cell, etc.
How the validation process should look like
The best approach, of course if possible, is to use ICA to verify the effectiveness of Permanent Corrective Actions, which is illustrated below in two scenarios. On the left is presented, an example with effective final action is shown, on the right with an ineffective one.
With this approach, is possible to monitor whether the level of nonconformities has been reduced to 0% after the implementation of the final action. If this level after the introduction of PCA is not equal 0%, it means that PCA is not effective and must be improved. In this situation, ICA must be continued until PCA is 100% effective.