In summary, a service such as Microsoft's Active Directory can make managing your network simpler and help to dramatically reduce the total cost of ownership. Without a similar service in place, it is well worth you making an analysis of the savings that could be made by moving towards AD.
In a report of this size, we can only give you a snapshot of some of these areas. Others can be found on the TCO saved from better security (see the AD Security paper - also on ITproPortal.com) and many other areas such as AD's fault tolerance. For further information see www.microsoft.com/activedirectory and www.getthefacts.com
Ben Chai is author of Migrating from Windows NT to Windows 2000 and has worked on several AD projects in the financial sector. He can be emailed via Ben@chai.co.uk
More special reports on Active Directory
Enhancing Security through Active Directory