At the Calculations, Schedule Options, in the Recalc Window, the user can select one of the following four possible options for the calculations in the schedule:

• LC by LC analysis: The usual Load Case by Load Case calculation, ideal for linear calculations or non-linear with only one load;
• Accumulate stiffness: For each Stage, the internal force state of the previous is considered in the calculations (accumulated); 
• Accumulate Perm. Loads: The permanent loads from the previous stages are accumulated (limits: no strain loads, changes in the structural system, or composite);
• Erection control: Similar to Accumulate stiffness, but the deformation history is fully considered in geometrically non-linear analyses;
  • with construction kink: Elements are placed with their design shape, with a length in the deformed position of the nodes they are connected to, including rotations (boundary conditions consistency needed).

Also, the Summation Load case can be defined: usually, it is created with a name or number, like STG-SUM or 1000, using the load management function. It's the load case where the current summation state due to previous permanent load cases is added.