IAM is a combination of processes, technologies, and policies enabled by software to manage digital identities in their lifecycle and specify how they are used to access resources. IAM is a superset of AAA (Authentication, Authorization, Auditing)*. Here are some general strategies for enterprise to consider:
*Note: Gartner and Forrester have 4 A's with additional Administration. Auditing is also referred as Audit or Accounting or Accountability.