Many of us are designing (or even optimizing) designs to meet "least mass" for one reason or another. This is a royal pain when we use lumped masses... in particular when there are lumped masses and multiple model tree levels of our simulation assembly AND rely heavily on shell and beam models that have no inherent mass except through running a simulation.
Currently the reported mass in the simulation report is the total mass of all beams, shells and lumped masses at all levels. This makes it royally painful and inefficient for me to report to my audience what the actual mass of my design structure is. I must carefully check every assembly and part to see if it has any lumped masses in it... and subtract those out of the mass value in the .rpt file.
A system measure called something like: "Sum of Lumped Masses", if it existed, could be subtracted from the current "total mass" to arrive at the mass of the design I am working on.