Completing a Rehearsal of Concept (ROC) drill is important before full scale roll-out. This can be done by simulating a live environment or completing the transition with a sample of users first.This sample of users could be super users or end-user volunteers but it’s always worth getting your customer base involved too. As well as providing valuable feedback on the transition process, these users, if all goes to plan, will become advocates of the new service. And if the ROC drill does go wrong, they are a voice and a powerful source of front-line insight.The test user sample size will depend on the organization, the complexity of the change and how many people it will impact. You should also make sure your sample comprises a range of users with different knowledge and experience levels.For these exercises, I often use scenario-based testing. For instance, for the network convergence project, we presented the scenario and asked each user to do certain tasks. We then evaluated whether they still had the right access and could do what they needed.Whether it’s a major strategic transition or moving to a new operating system, the purpose of the ROC drill is the same: can you still do what you need to do and is there anything you can’t?