Chapter 10Two Levels of Planning and Tracking
Agile plans at two levels: a series of course-grained release plans and a series of fine-grained iteration plans.
Planning is another area of significant difference between agile and waterfall methods. While agile methods may be considered by many (wrongly) to be relatively unplanned, in fact agile is a very disciplined process that involves continuous planning and updates. However, it is true that agile forgoes the traditional, long-range, detailed, monolithic PERT chart–like, predictive planning process. As Kruchten  notes:
There have been countless ambitious but doomed attempts to plan large software projects from start to finish in minute detail, as you would plan the construction of a ...