Hi Dan, Care to share your schedule? It sounds pretty interesting. Based on a quick read-through, I’d suspect issues with variable calendars. I remember being a fan of fixed-duration tasks when I started using MP for hard project scheduling, having had some years of P3 experience prior. Over time, however, the love faded. Fixed duration tasks in MP seem to be made using a collection of exceptions to the default rules; they constantly surprise me.
For most people, critical path analysis in MP is a hostage to the total slack calculation, which itself is a hostage to early and late date calculations that may not be carried out the way you expect…. Progress reporting, resource leveling, and variable application of calendars certainly complicate things…. Good luck tom