A shmoo plot shows the result of testing something while changing two variables. This is used in semiconductor manufacturing to test wafers. This concept could be used to help make retirement decisions. Example Shmoo plot images

One example is deciding on when a couple should take social security. We would first pick the variable we want to see the effect of, and then the two variables to adjust. In this case, we could choose net assets at end of plan and then claiming social security age for each person as the x and y variables. Projection Lab would then vary the claiming age for each person and produce a plot showing the net assets for each combination.

This would really help in try to make some decisions like: 1) how much to save in 401k vs Roth (dollars saved in 401k vs dollars saved in Roth) 2) When to stop saving in 401k (date vs dollars saved in 401k) 3) Check for holes in longevity risk for a couple (longevity age of each person in a couple) 4) Check for maximum spending (date vs dollars spent in retirement)

Income lab has something similar for their social security planning, but having the ability to pick any three variables would be amazing.

It would also be nice if these plots could be saved and presented as a collage. Then you might be able to see the effects across multiple variable sets in a single glance.

Somehow being able to solve for more that 3 variables would be great, but I can’t think of how to show it visually.

I think Compare Mode should let you do these kinds of comparisons today. Have you tried that?