You found the root cause now what do you do?

John W. Moran

When an improvement team finds the root cause or causes of their process improvement problem they usually start to develop solutions using a Solution and Effect Diagram.[1] The Solution and Effect Diagram produces a number of potential useful solutions that the improvement team must sort through and prioritize to determine which are the most practical to implement and achieve the improvement goals set forth in the AIM statement. The prioritization process can be a confusing and time consuming process for an improvement team since they need to develop criteria to prioritize the solutions against, develop a rating scale, achieve consensus, and then do the prioritization.

To help simplify the prioritization process an improvement team can use a Solution Prioritization Tree. The Solution Prioritization Tree starts when the team has discovered the root cause or root causes of their process improvement problem and they have a number of potential solutions to evaluate as shown in Figure 1.

The Solution Prioritization Tree has a number of sections on its branches that the Improvement Team needs to fill-in to help in their analysis and prioritization of the potential solutions. The various sections of the Solution Prioritization Tree are a cluster of factors that helps the team to map the relationship between the problem, root causes and solutions. This process is useful since it helps the improvement team to:

  • ensure the solutions will bring about change that impacts the goals in the AIM statement positively
  • ensure the solution(s) selected address the significant main cause(s)
  • ensure that any solutions considered improve customer satisfaction with the process being improved
  • guide the team in determining the effectiveness and implementation of their solutions
  • help the team evaluate which solutions should be implemented

Constructing a Solution Prioritization Tree involves the following steps:

  1. Draw a Solution Prioritization Tree for each root cause found in the Cause and Effect diagram as shown in Figure 1.
  2. Label the front left box with the root cause name.
  3. List potential solutions developed on the Solution and Effect Diagram which address the root cause and place those in the boxes labeled Potential Solutions. Only three potential solutions are shown in Figure 1 but there may be many more.
    1. In the box labeled Improvement Steps detail the specifics that would be required to implement the potential solution attached to it.
    2. Develop a consistent set of Prioritization Criteria to rate each potential solution and its associated methods and tasks required to implement it. For this example we have used the following three criteria:
      1. Impact on the AIM Statement goals – will this particular solution contribute to achieving the goal(s) detailed in the AIM Statement
      2. Implementable – is the solution one that can be implemented easily and be cost effective.
      3. Improve Customer Satisfaction – improvements will increase customer satisfaction

Depending on the particular problem being solved other prioritization criteria may be more applicable and should be used. It is permissible to use more than three but too many criteria can make the prioritization process complicated and not user friendly.

  1. Rate each of the solutions on the three criteria that are chosen. Use the following rating scale for each of the prioritization criteria to see if improvement will be made in the process being improved:

Rating Scale



Customer Satisfaction


No Improvement

Not Feasible

No Improvement


Minor Improvement

Some difficulty




Major Improvement

Somewhat easy

Major Improvement


Significant Improvement


Significant Improvement


  1. Impact:

0 – no improvement will be achieved in the process

1 – minor improvement will be achieved in the process

3 – major improvement will be achieved in the process

5 – Significant improvement will be achieved in the process


  1. Implementable:

0 – not feasible to implement

1 – Implementable but with difficulty

3 – Somewhat easy to implement

5 – easy to implement

  1. Customer Satisfaction

0 – no improvement in customer satisfaction

1 - Minor improvement will be achieved in customer satisfaction

3 – Major improvement will be achieved in customer satisfaction

5 – Significant improvement will be achieved in customer satisfaction

  1. In column one the improvement team should decide the appropriate rating on this particular solution and how it will Impact the goals set forth in the AIM Statement. Each potential solution should make a contribution to achieving the desired future state of the process being improved. Usually, no one solution will achieve the total improvement but a few solutions when implemented in parallel will accomplish the desired change.
  2. In column two the improvement team should determine how Implementable the proposed solution will be. A solution that is implementable is one where the changes to the process can be accomplished quickly, with minimal costs, and will be accepted by those doing the work.
  3. In column three the improvement team needs to decide how Customer Satisfaction will improve with the proposed improvement to the process.
    1. In column four multiply the rating in column one, two, and three together to get a total score for each potential solution
    2. In column five the improvement team makes a Decision on whether or not to adopt the solution and implement it - (Yes/No).

To determine how many solutions to implement the improvement team needs to develop a project plan showing the sequencing of those potential solutions that scored high, resources required to implement them, timing, responsibilities, and targets to be achieved. This will give them an idea of how much they can take on to achieve the improvements desired.


Example: Approved Vacant Position Not Being Filled Quickly:    

vacant position


[1] The Public Health Quality Improvement Handbook, R. Bialek, G. Duffy, and J. Moran, ASQ Quality Press, 2009, pp. 185-188