© 2017 IEEE. A configurable Business Process (BP) is an abstract BP that engineers customize with respect to specific requirements. To keep track of the multiple and recurrent customizations that lead to a set of derived BPs, this paper proposes a knowledge-based approach that uses a new Process Structure Tree called configurable PST (cPST). A cPST abstracts a separate variability option of the configurable BP. All cPSTs should be equivalent to the set of all PSTs associated with the derived BPs that could originate from the same configurable BP. This paper also proposes a logic-based configuration model for capturing configuration details on the cBP and describing the cPST computing.