Abstract: An Internet-based system and method is set forth for estimating power availability and business process downtime based on specific attributes of a building and business process components contained therein. The system includes a power availability estimator computer coupled to a plurality of user computers via a computer network. The power availability estimator computer can be programmed with a power availability estimator engine, which calculates or estimates the probability that electrical power will be available and/or downtime for a particular building on an annual basis. The power availability estimator engine includes a plurality of equations that cooperate with a probability density function graph to calculate the estimated power availability and business process downtime.