Methods and systems for modeling functional processes in enterprises, and for simulating and valuing the effects of various products and services on those processes, are described herein. The cost of disruptions in service of commercial fleets of transportation vehicles such as aircraft, is assessed. The causes of the disruptions are determined and for each such cause, disruption events are classified according to their duration. The cost factors are established and then accumulated to reflect the cost per cause and severity of disruption. Curves are developed that allow users to identify the disruptions that are most costly.