Decision Tools for Vendor Selection Tour Methodology The Decision EngineTM breaks complex decisions down into a multi-level hierarchy. Using a mathematical methodology (Refined Hierarchical Analysis), the software lets you define the relative importance of the criteria in the hierarchy and then ranks the vendors based on your preferences. Let's start by exploring the hierarchical view of the model for CRM evaluation and selection. (Click to view detail) Contact Information: For more information on Decision Tools for Vendor Selection please e-mail DTforVS@gartner.com.