Let’s talk about the ways of classifying the projects (not very serious).
1. To earn a money
There are the projects with direct impact on revenue, profit, cost. For instance, a change to a more productive technology, cutting expenses.
Outcome is estimated in money.
2. To mitigate some risks
These are the projects about a better manageability or directly related to an identified risk. For example, improving release or incident management in IT.
Lower risks (probability * possible impact) should be the outcome of this kind of projects.
3. To gain more loyalty
It should be a project about customer’s loyalty. I believe that quality perceived by customer also converts to loyalty. That’s why quality projects (making a service faster, stronger, better and customer journey easier) fall into this category.
Value can be measured in NPS and churn decline.
4. For passion and pleasure
Outcome can not be measured. You are engaged, maybe, to someone else’s loyalty project (type 3). But, anyway, probably, these are the most valuable projects.