Microsoft Exchange Server is a mail server, calendaring software and contact manager.
It runs on Windows Server and it is one of the main elements present into a Microsoft infrastructure.
It often happens that one of the first requirements of an identity manager project is to integrate Microsoft Exchange in order to manage, into the global/centralized user workflow, mailboxes and mail contacts as well.
Windows PowerShell is a command-line shell and scripting language designed especially for system administration.
Its cmdlets let you manage computers and all server-side Microsoft applications (e.g. Exchange, SharePoint, FileServer, Active Directory, ...).
Windows PowerShell gives you the possibility to perform all common administrative tasks ... including provisioning operations! ...
It has been long time since I have been listening always to the usual complains about the big mess caused by the attempt to reflect and manage own organization using Active Directory groups.
Often Active Directory is used to centralize all the information about authentication and access to the services/resources of a certain network domain.
Problem always arises when the number of such resources becomes so that high that groups are not an handful mean any more. Provisioning, deprovisioning and [business] roles management easily become expensive (in terms of effort and time) and risky (in terms of access permissions) operations.