A method includes receiving test objective data indicates an objective to be achieved during a cybersecurity test of a target system. An attack tree is generated by processing the test objective data into attack tree data including a plurality of data parameter sets and links between data parameter sets. Complexity of the attack tree is analyzed based on the test objective data using a combinatorics model. The attack tree is reduced to achieve the objective of the cybersecurity test based on the analyzed complexity of the attack tree.