1. A business process model simulation method comprising: loading a business process model for simulation; designating a decision node in the business process model as a master decision node and linking another decision node in the business process model as a slave decision node to the master decision node; simulating the master decision node to select an output pin and storing the selected output pin in association with the master decision node; and, applying the selected output pin in the slave decision node when arriving at the slave decision node during the simulation without simulating the slave decision node.