Performance/availability modeling with the TANGRAM-II modeling environment

TANGRAM-II is a modeling environment developed for research and educational purposes that provides a flexible user interface to describe computer and communication system models. It is based on an object oriented description language and has a sophisticated graphic interface built from the public domain software package TGIF (TANGRAM Graphic Interface Facility). The current version is implemented in C++ and C and has several solvers for transient and steady state analysis of performance and availability metrics. Several examples that we present highlight the modeling capabilities of the environment.