I was teaching a class, introduction to project management in the context of product development, and we explored the impact of a dynamic or shifting scope and the impact on project management success. No matter your project approach (conventional or agile) some mechanism for managing the scope. In agile, we recognize change will happen, however, the change is undertaken at very specific times. That is, there are controlling mechanisms for the change. For example, if in our sprint, we learn something that requires changing, we will undertake that change, perhaps, in the next sprint and not our present work. This change, will have to make it past the grooming activities in which the Scrum Master will ensure the material is ready to be executed upon. In our conventional project, the requirement change will be understood, including cost, time and risk consequences. Once this is understood, the customer and the project owner will arrive at whether the change will be accepted.

The manner we take to manage the requirements, or not, will have an impact on the probability of success.