Figure 2.21 combines the previous flow diagrams for limit state STR. Actions (characteristic 6 representative 6 design) are shown down the left-hand channel; geometrical parameters (nominal 6 design) down the central channel; and material properties (characteristic 6 design) down the righthand channel. The introduction of combination factors ψ, partial factors γ, and tolerances Δa at appropriate points in this process is shown.