Dynamic Systems Development Method

DSDM is an agile software development methodology. It is an iterative, incremental approach that is largely based on the Rapid Application Development (RAD) methodology. The method provides a four-phase framework consisting of:
Feasibility and business study
Functional model / prototype iteration
Design and build iteration

Books Recommended:

DSDM: Business Focused Development (Agile Software Development Series)
by DSDM Consortium and Jennifer Stapleton