It is usually recommended that these projected statements be on a monthly basis for at least the first twelve months or until the business is projected to be profitable and stable. Activity displayed beyond the monthly detail may be in summary form (such as quarterly or annually). The forecast period for most business plans is two to four years.
If you have not already, setting up a capital committee to review expenditures in advance of the start of the project provides some assurance that the projects have been vetted against return on investment. Lastly, developing a post-audit process enables the team to review and monitor the progress of ongoing investments.