Compartmentalizing your plan by developing planning modules allows you to attack the plan in parts, yet still maintain a cohesive plan. I have found that developing an annual plan made up of quarterly targets - thus becoming a rolling quarterly forecast financial model - allows for a cohesive structure along with the nimbleness to react to market conditions. At the end of each quarter, a true-up process to align results to annual targets needs to be re-forecast and adjustments made.
Remember not to double-dip on the capital projects EBIDTA contribution for the upcoming year - your budgetary baselines should move in concert with these investments. All projects that straddle the budgetary year, should be rolled over into the new plan. Business planning is the road map that identifies where you are headed in advance.