1.3.  User Requirements Document

At the beginning of Geant4 development, a set of user requirements was collected in order to inform the object-oriented analysis and design of the toolkit. The User Requirements Document follows the PSS-05 software engineering standards and is available at

http://cern.ch/geant4/OOAandD/URD.pdf .

This document provides a general description of the main capabilities and constraints of the toolkit. It also defines three types of users characterized by their level of interaction with the system. Specific requirements are also listed and classified.