This document describes how to use Google Cloud tools to troubleshoot use cases related to problems accessing Google Cloud resources. This document doesn't describe how to troubleshoot end-user access to your applications. This document assumes that you're familiar with Troubleshooting policy and access problems on Google Cloud. The troubleshooting policy and access problems document describes Google Cloud services that can enforce access policies and the troubleshooting tools that Google Cloud provides.
https://cloud.google.com/architecture/troubleshooting-policy-and-access-problems-use-cases
