A computer implemented Availability Checking Tool enabling tool users to execute within a common work environment, from common enterprise data, and considering assets and demands across multiple order management systems and manufacturing facilities within boundaries established by manufacturing specifications and process flows and business policies. The tool receives orders from multiple demand sources or ordering systems. Tool users can easily maintain a synergistic relationship between multiple ordering systems. A demand configurator coordinates product requests based on information from the demand source according to certain rules and priorities assigned to the product requests. A material resource engine manipulates data from the demand configurator and the rules to provide material supply information. A solver manipulates the material supply information from the resource engine and the rules to provide optimized product availability information. Thus, customer business rule level definitions are supported to provide the tool users with the power to micro-manage, optimally, enterprise assets and demands.