Phoenix Project Manager has the ability to calculate your schedule by Longest Path. Longest path is a way to sometimes see what your "real critical path" is.   Basically Longest Path is a calculation of the schedule that ignores Finish-No-Later, Start-No-Later, Must-Finish-On, and Must-Start-On constraints.   If you look at the example above you can see that there are activities with Path Float that differs from Total Float (TF column). The reason they are different in this example is because of a Finish no Later constraint on Activity PH1762 that causes the activity to have -6 days of total float but its path float is 8. In the longest path the Path Float only considers the relationships, this means that constraints that affect the float are ignored.   Phoenix is the only program, (to our knowledge) that shows what we call Path Float. You also have the ability to change both number of days of Path & Critical Float to display as Red to view what is near critical or near longest path.