An effective lighting planning tool is the lighting system inventory. The lighting system inventory is a detailed survey of the facility that is used to determine the lighting requirements of all spaces. It identifies what is installed where, how it is controlled, and when lighting is required. It then identifies areas where the existing lighting system fails to meet the needs of the occupants or requires excessive energy to operate. One of the most important factors in maintaining the long-term efficiency gains achieved by a lighting retrofit project is flexibility.
Facilities are in a constant state of change.
Lighting needs change. If the facility's lighting system is to continue to meet the needs of the occupants, it too must have the ability to change. The net result of this mismatch will be the addition of new lighting fixtures and the bypassing of lighting controls, both of which decrease the operating efficiency of the system. Building in flexibility during the planning stage will allow fixtures to be moved, added or deleted as required when changes take place. Good maintenance practices will limit light losses due to depreciation of the lamps and fixtures, and accumulation of dirt on fixture surfaces.