A method and system are provided by the present invention for developing functional software element that operates in an environment comprising a plurality of computer programs that are being simultaneously developed. A test facilitating computer program product is utilized to simulate the plurality of computer programs as seen by the functional software element. The functional software element has one or more internal software interfaces that interact with one or more simulated external software interfaces to provide an environment in which the operation of the functional element and the internal software interfaces thereof can be monitored. The test facilitating tool permits creation of files that may be utilized to create an operational scenario during which messages that are received by and sent from said functional software element can be monitored.