This document discusses two approaches to single sign-on (SSO): web access management (WAM) and open standards like SAML and OAuth. WAM uses policy enforcement points to intercept requests and enforce security policies, while open standards pass identity between an identity provider and applications. Both approaches can meet different needs, and choosing the wrong one can increase costs and cause delays. The document provides guidelines for choosing between the approaches and notes that they can be combined to get the benefits of both within a single SSO solution from CA Technologies.