Brainstorming

 To begin the brainstorming process, you must assess the risks that could impact your project. This starts with reviewing the project documentation, looking over historic data and lessons learned from similar projects, reading over articles and organizational process assets. Anything that can provide insight into issues that might occur during the execution of the project. Once you’ve done your research, start brainstorming with anyone who might have insight.

A variant of this is the Delphi technique, which is when a request is sent to experts and they reply anonymously. Or the project manager can interview experts, team members, stakeholders and others with experience in similar projects.