The main features of CalcHEP are the computation of Feynman diagrams, integration over multi-particle phase space and event simulation at parton level. The principle attractive key-points along these lines are that it has:
a) an easy startup even for those who are not familiar with CalcHEP
 b) a friendly and convenient graphical user interface
c) the option for a user to easily modify a model or introduce a new model by either using the graphical interface or by using an external package with the possibility of cross checking the results in different gauges
d) a batch interface which allows to perform very complicated and tedious calculations connecting production and decay modes for processes with many particles in the final state.

With this features set, CalcHEP can efficiently perform calculations with a high level of automation from a theory in the form of a Lagrangian down to phenomenology in the form of cross sections, parton level event simulation and various kinematical distributions.