This paper considers the application of the structured singular value, μ, and the skewed structured singular value, abbreviated “skew μ”, to the analysis of a (deceptively) simple MIMO mass-spring-damper system. This example highlights some pertinent outstanding μ analysis questions, namely the effect of strictly real, possibly repeated parameters and the limitation of classical grid-based methods. It is shown that by transforming the original μ problem and using skew μ to calculate the worst case that more reliable and certifiably safe answers to the analysis question are determined. A comparison with more conventional μ analysis methods is presented.