When you work on a Lean Six Sigma project, you go from problem to causes to solutions. But how do you choose between all those good improvement ideas? That is what the Impact Effort Matrix is for, also called the Ease/Impact Matrix.
What is the Impact Effort Matrix?
In the DMAIC cycle of a Lean Six Sigma project, the Improve phase is about coming up with improvement ideas. For many people it is secretly the most enjoyable phase, and it usually produces far more ideas than you can carry out at once.
The Impact Effort Matrix helps you sort and choose those ideas: which do you tackle straight away, which do you plan, and which do you leave?
How does the Impact Effort Matrix work?
The matrix has two axes:
- Impact: how much does the idea contribute to solving the problem? The more impact, the higher the idea sits in the matrix.
- Effort: how much time, money and energy does it take to implement the idea? Building support counts too. The more effort, the further to the right.
By placing each idea along both axes, it ends up in one of the four quadrants. The quadrant decides what you do with it.
The four quadrants
- Do now (high impact, low effort): the pick of the bunch. These ideas are the most promising, so you start on them straight away. Many sources call this quadrant quick wins: they show results fast and give the project momentum.
- Plan (high impact, high effort): valuable, but not simple. Think of automating a process or hiring extra people. You put these ideas in a plan, with time, budget and an owner.
- Fill in (low impact, low effort): easy to do, but they don’t solve the problem. Pick them up when there is room, without distracting from the big improvements.
- Don’t do (low impact, high effort): a lot of work for little result. These ideas are not worth it.
The image at the top of this article shows an example: seven ideas for shortening customer service waiting times, spread over the four quadrants.
Deciding the quadrant together with n/3
Where an idea belongs in the matrix is best decided together, right after the brainstorm. A handy method for this is n/3 voting.
- Count the number of ideas (n) and divide it by 3. The result, rounded down, is the number of votes each team member may cast.
- Each team member gets that number of red dots for impact and the same number of green dots for easy to implement.
- Everyone places their red dots on the ideas they think have the most impact, and their green dots on the ideas that are easiest to implement.
- Lots of red dots means high impact, lots of green dots means low effort. That is how you fill in the matrix.
Voting quickly gives a shared picture, but it remains an estimate. Where possible, back up the impact with data, for example the measurements from the Measure phase.
This is one of the tools you learn to apply in the Green Belt training.
What next?
Once the improvement ideas have been chosen and put in order, you include them in your implementation plan. If you work in an Agile or Scrum environment, they are good input for the backlog. Otherwise you could plan the implementation with a Gantt chart, for example.