General Features - STAAD\Pro-QSE  utilises first order elastic analysis theory. It has two separate analysis engines available.  The Standard engine for general usage and an Advanced engine that provides the user with a greater range of options.

Standard Engine
1000 Node, 2000 Elements. 2D / 3D functionality. Fast and efficient decomposition of the stiffness matrix using the Choleski method. Wide range of beam and node loads, including point, distributed and thermal loading. Prismatic and tapered I sections supported.
Advanced Engine
Model size limited by computer Upto 60 times faster than the standard engine on large models. Support for 'Rigid Offsets' to model beam eccentricities. Support for 'Spring Connections' to model non-rigid connections. Enhanced range of loading that includes moment loads along beams and thermal loading that vary across the cross section. 'One-Way' analysis. Two-step analysis that can be used to remove bracing that show as compression in a standard first order elastic analysis. 'P-Delta' analysis option.  Iterative process can be used to identify potential buckling loads.