Expert judgment

If there's one tool that is utilized more than any other in project management, it would be expert judgment. Whether it's the beginning, the middle, or the end of the project, utilizing expertise from a variety of stakeholders, subject matter experts, consultants, and business analysts makes good sense. In project selection, there will be numerous key stakeholders involved who have a variety of historical information, lessons learned, and even opinions as to which projects should be selected.

The downside to using only expert judgment to select projects is the potential for groupthink. Groupthink is when a group of people are trying to make decisions they all agree on and the stronger personalities believe they are correct and convince others to go along with their ideas. The problem arises when the group is closed to outside ideas and alternatives, and the decision-making becomes irrational or counter-productive.

Unfortunately, some organizational politics are key influencing factors in project selection. This is why CompTIA recommends knowing other project-selection techniques, such as those you just covered (at a high level at least), so if you are providing expert judgment on the development of the business case, you know what you're looking for and how to make the best decisions.