Load cases
Cases on the rail keeps several load configurations on the same structure. A new case starts as a copy of the current one; give it a type (Dead, Live, Roof live, Snow, Wind, Seismic or Other) and a name.
Combinations add the cases with factors, such as 1.2D + 1.6L, with shortcuts by case type. Compare cases shows them side by side, and Worst case gives the envelope of all of them.
Self-weight
Turn on self-weight in a load case and each member adds its weight ρ·A·g, downward. It needs a material with a density and a section on every member; the app tells you which member is missing them.
Unknown loads
Mark a load as unknown (P = ?) and add the conditions you know, such as a reaction, a member force or a moment at a section. The app solves for P. A target FS can fix the unknown too: the largest load the structure can carry.
Solve for a parameter
Solve for a parameter finds a section dimension, an area, a second moment or Young's modulus. Size it finds the smallest value that meets a minimum FS or a displacement limit; Match a measurement finds the value that reproduces a measured displacement. Apply to model writes the answer, and Undo restores the previous value.