"Fixing" the root cause is often called a Corrective Action Plan. According to the standard AS9100 - 8.5.2 Corrective Action:

The organization shall take action to eliminate the causes of nonconformities in order to prevent recurrence. Corrective actions shall be appropriate to the effects of the nonconformities encountered. A documented procedure shall be established to define requirements for

  1. reviewing nonconformities (including customer complaints),
  2. determining the causes of nonconformities,
  3. evaluating the need for action to ensure that nonconformities do not recur,
  4. determining and implementing action needed,
  5. records of the results of action taken (see 4.2.4),
  6. reviewing the effectiveness of the corrective action taken,
  7. flowing down corrective action requirements to a supplier when it is determined that the supplier is responsible for the nonconformity,
  8. specific actions where timely and/or effective corrective actions are not achieved, and
  9. determining if additional nonconforming product exists based on the causes of the nonconformities and taking further action when required.


Thus, to address (fix) the root cause, potential root cause solutions are evaluated, a solution (or combination of solutions) is selected, the action plan is developed, and the solution is implemented and verified. In addition, a good solution will keep the problem from occurring again and is practical, feasible and cost-effective as well as robust and sustainable.

Evaluate potential solutions

  • Combine solutions that are similar or are extensions of each other.
  • Screen solution candidates for practicality, feasibility and cost-effectiveness; delete those that fail these tests.
  • Select the best solution:
    • Develop a criteria and an approach to be used to evaluate solution candidates against that criteria.
    • Decision Matrices can aid decision-making; many types of matrices are available to help evaluate solution candidates including:
      • Pros & Cons Matrix
      • Force Field Analysis
      • Plus-Minus Attribute Rating
      • Musts and Wants Analysis
      • Nominal Group Technique
      • Voting and Ranking
      • Kano Analysis
      • (Is one technique better than another? That is up to you to decide.)

Develop and implement the action plan

  • The action plan outlines what steps are needed to implement the solution, who will do them, and when they will be completed.
  • Simple Action Plans have a "who, what, & when" format.
  • Complex Action Plans often use PERT and Gantt Charts as action planning tools.

Verify the action plan

  • Verify that the solution works as designed.
  • Always check to see if the solution creates new problems by checking with the users, asking specific questions on use, usability and performance. To verify, ask:
    • Does it work?
    • How well does it work?
    • Does it work for all conditions and all participants?
    • Does it create other problems?
  • Adjust the solution quickly if:
    • Instructions are unclear
    • Using the solution creates confusion
    • The solution creates other problems