I am trying to write an iif equation that doesn't involve a numerical value, but simply whether a feature is suppressed or unsuppressed. I am using SW 2011 on an assembly with several subassemblies to have parts automatically update from one driving dimension change. I have created the following equation: "WATERFALL"= iif "RIGHT PLANT ON -- PLANT ON BACK.Part" - .75, "unsuppressed" , "suppressed" ) but this does not change the assembly. What am I missing? Thanks.