You are a PM @ Google Cloud and you realized that for a set of users VMs (Virtual Machines) have been underutilized or not utilized at all. How do you identify the root cause and how do you solve and ensure that the issue won't happen again?

You are a PM @ Google Cloud and you realized that for a set of users VMs (Virtual Machines) have been underutilized or not utilized at all. How do you identify the root cause and how do you solve and ensure that the issue won't happen again?