Another important element is modularity. Units are encapsulated and parametrized, which makes it straightforward to configure detailed equipment: splitters, heat exchangers, compressors, reactors (with several reactor models), and various types of separation units. More advanced users can assemble complex sequences — multistage columns with interstage feeds and side draws, integrated heat-pinch networks, or recycle loops with convergence strategies — and rely on robust numerical solvers to find steady-state solutions. For many engineers, the quality of a simulator is judged by how it handles difficult convergence cases; Chemcad NXT invests in solver options, initialization strategies, and under-relaxation controls so users can guide or automate solution finding.