To build a robust Identity and Access Management (IAM) system, consider these key elements:

1. Centralized Identity Management: Use a single system to manage user identities, ensuring consistency and security across the organization.
2. Role-Based Access Control (RBAC): Assign permissions based on roles rather than individuals, simplifying management and improving security.
3. Multi-Factor Authentication (MFA): Implement MFA to add an extra layer of security without overly complicating user access.

In a multi-cloud environment, managing identities and access rights can be challenging. Here are some strategies:

1. Unified Access Policies: Establish consistent access policies across all cloud platforms to maintain security and streamline management.
2. Federated Identity Management: Use federated identity solutions to allow seamless access across multiple cloud services with a single set of credentials.
3. Automated Provisioning and De-provisioning: Automate user access provisioning and de-provisioning to ensure timely and accurate access control.

To implement MFA effectively without disrupting user experience:

1. Adaptive MFA: Use adaptive authentication that adjusts security requirements based on user behavior and risk levels.
2. User-Friendly Methods: Offer multiple authentication methods (e.g., biometric, SMS, authenticator apps) to provide convenience and flexibility.
3. Single Sign-On (SSO): Combine MFA with SSO to reduce the number of login prompts, making access easier while maintaining security.

By integrating these elements and strategies, organizations can manage user identities and access rights effectively while ensuring a smooth user experience.