CUA and IDM

IDM - Identity Management. 

Gets connected to ABAP system + NON ABAP systems + third party tools 
Adv of IDM : Self service password reset. 
IDM : can be connected and used in combination with an existing CUA. 
or if CUA is not installed ,you can directly go for IDM. 
Enables workflow-based requests for approvals, automating user provisioning 
in multiple back-end systems 
Supports LDAP directories and databases, as well as standards such as SPML 
Supports tight integration with SAP Business Suite 7.0 . 


CUA is central user administration 

Its a central system where where we maintain / create users. 
For instance : you have 30 systems installed (like ECC6.0 (dev / QA / PROD), 
SRM,BI,CRM...) 
if u get a request from client saying you need to create 50 users in 30 
systems (ie u are giving access to the users in 30 systems). 
So what you do - in each and every sytem u need to create users (user 
creation independent of other system / clients) its a tedious process. 
if at all you have central system(CUA) install,then within 3 to 5 sec you 
will be able to create 50 users in 30 system. 
it enables you to manage several thousand users and their individual role 
assignments. 
How to know that CUA is installed in ur company- Su01 -Create /change user 
-> if you notice "system tab" other than role, profile , logon...then it is 
CUA. 
CUA gets connected to all your child system (BI,SRM,ECC...) using ALE / IDOC 
method. 
CUA only get connected to ABAP systems. 
If at all user wants to reset password / unlock he needs to approach help 
desk / security team 

Cheers