Once you have identified a potential solution, test it with a small-scale pilot project. This will allow you to assess whether your proposed changes achieve the desired outcome, with minimal disruption to the rest of your operation if they do not. For example, you could organize a trial within a department, in a limited geographical area, or with a demographic.

As you run the pilot project, gather data to show whether the change has worked or not. You will use this in the next stage. 

Note:  In this situation Do means “try” or “test”.  It does not mean you implement fully.  You only implement in the Act stage.