In the sensitivity analysis feature, the sensitivity of material parameters can be investigated: e.g. the influence of the displacements in node A for phase 2, or the stresses for a stress point. For Safety phases only, the sensitivity of parameters for the factor of safety (ΣMsf) should be available. But in PLAXIS 2D 2011, the phase type is not detected correctly in the Sensitivity analysis tool when viewing the sensitivity analysis results, and as a result the Factor of Safety option is not available.
This issue is fixed in PLAXIS 2D 2011.02