A configuration method and apparatus for a complex product or service that uses a reduced form of a prime rule indicative of valid and invalid configurations. The configurator applies user inputs parameters to an execution module that is constructed using directed acyclic graph, e.g., a zero-suppressed binary decision diagram, indicative of the valid or invalid product/service configurations. The results of execution may include conflict and selection advice to help guide the user to achieve a proper configuration. Elective events, such as but not limited to the display of messages or the performance of calculations, may optionally be packaged along with the prime rule or components thereof, and presented during execution to help guide the end user when choosing among possible configuration parameters. The apparatus and corresponding method automate determination of a complex configuration rule having a combinatorial exploded number of rule components, or a combinatorial number of possible outcomes, exceeding computational capacity of present day computing systems.