There are 4 questions that must be answered during the course of any project. These question are unrelated to the type of project.
- What capabilities does the project's solution need to provide the buyer to fulfill the mission or the business case?
- What technical and operational requirements are needed to fulfill these capabilities?
- What is the plan for implementing the components of these technical and operational requirements?
- During the development of these components, how can we tell we are making progress to plan?
No matter what method is used, no matter what the domain or context, if we can't answer these questions at all times, then it is likely the project will be late, over budget, and a disappointment to the buyer.
We could be building bridges, build spacecraft, building software with your favorite method - agile or traditional. These are the irreducable attributes of a project that need to be "managed" in some way.