Set up and activate a new plan when you need to pick up the latest information from Live forecast.  A snapshot of Live forecast is taken at the point the plan is created. 

While you can submit a plan to cockpits at any point to pick up the latest pricing in cockpit targets and cost forecasts this will not incorporate new updates to Live forecast. 

So, it is recommended to establish a regular schedule for focusing on rooms/revenue forecasts, then other drivers/cockpits and then taking the snapshot before focussing on the financial elements.