As a general rule, ongoing application costs are about 40 percent to 60 percent of the original development cost for each year in an application's life cycle. These are the costs associated with application support, maintenance, operations, software licenses, infrastructure, and allocated help desk and operational staff.
Controlling these ongoing costs is critical; as a component of baseline costs, they're necessary evils.

Collect and maintain information about all new development work underway throughout the entire enterprise and actively participate in all projects as a value-added business partner. Communicate effectively and relentlessly; report to senior management anticipated costs both at the start of projects and at appropriate intervals thereafter. Don't forget to maintain a historical record of all costs.