SaaS brings a lot of advantages to businesses - no need to invest in purchasing and maintaining licenses and infrastructure, and no need to worry about upgrades and bug fixes. Larger companies, however, face a major challenge related to user authentication and management. Larger companies have invested a lot of time and effort in improving user productivity, compliance and security, and in cutting user management costs. They have done so using technologies like single sign-on and centralized user management. SaaS applications are now challenging those efforts and threatening to bring them back to the situation where every user has several different usernames and passwords and the customers have several different user directories to maintain.