A computer-implemented method, apparatus or computer-readable medium to provide selection advice during rule processing to help a user choose desired specifications of a product, service, or other rule-based system characterized by a ZDD rule model having one or more Include and/or Exclude rules. One aspect includes displaying on a monitor or other I/O device multiple attributes having multiple enumerations that identify possible feature, specifications, or conditions of a product; selecting multiple alternative enumerations of the attributes; determining a selection advice for each enumerations selected combining the selection advice for each numerations in order to produce result; communicating the result to an end user; and then using the result to choose a product having desired compliant specifications or conditions.