In the world of software, especially when using agile methods, programmers design tests at the same time they code, so they can make sure their software works.
This same idea can be applied to management (strategy, planning) and government (laws): As you create the strategy, plan, or law, also design tests that will let you know if you are experiencing success, or if you need to change something.
The test will probably be a KPI, with a pre-determined value that signifies success or failure.
For example, a plan could be: "to address our current sales slump, we will change our commission structure".
We could add, "if we do not see at least a 5% increase in sales six months after the training, we will try to find an additional solution. If sales drop more than 2%, then we will immediately revert back to the old commission structure".