Time-consuming tasks Computer software 6 Atomic models 4 Automata theory 4 Computation theory 4 Computer architecture 4 Coupled models 4 DEVS models 4 Distributed computer systems 4 Distributed timed model-checker 4 Graph theory 4 Graphical editors 4 Mathematical models 4 Matrix algebra 4 Model re-use 4 Model-checking 4 Problem solving 4 Program processors 4 Real time systems 4 Set theory 4 Timed automata 4 Computer simulation 2 Discrete event simulation 2 Discrete event systems 2 Java programming language 2 Model and simulation 2 Modeling and simulation 2 Simulation result 2 Software design 2 Software development 2