This activity is part of the Cycle Planning. Each cycle is a month, and starts by detailing the high-level plan created in the Preparation for the upcoming month. This section shouldn't take more than 3 days.
When the monthly planning is done, the Sponsor has to make a new Go/No-Go decision based on the Business Case. This is to make sure the project is still justifiable, and reminds everyone that there’s a goal to the project, higher than the isolated specialist activities.
If it’s decided to stop the project, the Closing activities will be run, and you can decide whether or not to have the Post-Project cycle.