Barry Boehm and Richard Turner describe home grounds for Agile and Plan driven methods in their book "Balancing Agility and Discipline". They conclude that there are five critical factors that need to be evaluated for agile vs plan driven suitability. These are:
- Criticality
- Culture
- Dynamism
- Personnel
- Size

In the above example, we see that project whose chart is described in red, has certain ratings towards the peripherals. The culture of the organization is more accustomed to plan driven methodology and the number of people in the project is about 40. Scrum and other agile techniques do not work very well with team sizes greater than 10 or 12. On the other hand, the requirements seem to be quite volatile. This is a classic case where a hybrid of plan driven and agile based methodology is required. Iterative development will best serve the dynamic requirements, but culture and size pose challenge to running in agile.
Let us consider an example of development of a software that is used to provide key information to pilots about the aircraft in flight. Such a software is highly critical and defects in such a software can result in the loss of many lives. This kind of a project will be rated at an extreme peripheral of the criticality dimension in the chart. By doing such an analysis, an organization can identify risks by moving to agile and plan risk management approaches to manage these risks.
References:
Balancing Agility and Discipline, Barry Boehm & Richard Turner, 6th Printing, Feb 2008