A public policy is shaped through something called "Public Policy Cycle". It consists in 5 stages, starting with the agenda.
The agenda is a setting of problems and concerns that governors and implementors need to analyze in order to find the one they will address at the moment.
After the problem is chosen, the other stage of the cycle is the "formulation", which consists in creating the policy itself, all the people that are going to be addressed with that policy, how it is gonna affect these people, etc.
Then, the "implementation". In this stage, the policy is effectively implemented, and starts working.
And last, the "evaluation". Evaluation is the stage when the governors and implementors get to see the outcomes of the policy, and then formulate and implement changes to improve it.
