T-Mobile has been using Splunk for operational intelligence over three generations. They initially extended their service assurance tool suite with Splunk, then increased capacity and developed high-profile use cases. They now have Splunk integrated with other tools and provide self-service capabilities to users. T-Mobile provides a Splunk service portal for users to access documentation, training, and forwarder installation instructions. They also have a service catalog for managed and self-serve options. T-Mobile uses Splunk across various ITSM processes like incident management, problem management, and change management. They take a balanced iterative approach to their Splunk program management.