The invention provides a method for extracting and evaluating risk information and synergy information arising out of role relationships among persons which are an essential part of a business process and realizing a safe and appropriate business process.A business process design support system in the invention includes: the business process definition unit 201 of the business process definition system 2 which receives role relationship information defined by a designer, etc. and transmits the information to the risk/synergy evaluation system 3; the risk/synergy extraction unit 301 which extracts risk/synergy factors and occurrence mechanism information based on the role relationship information; and a risk/synergy measures evaluation unit 401 which calculates risk/synergy measures candidates and estimated effects based on the risk/synergy factors and the occurrence mechanism information.