It is suprising to me that in consideration of the potential major sources of constraints and the necessary PMs focus on managing them (i.e.cost, time, scope, being the most referred to and then the others as well . . . risk, quality,etc) and that standard project plans (i.e. any artifact referred as a management plan and are subsidiary to the actual "project management plan") that some management plans are identfiied in ITTOs as specific outputs while others are not.

For instance, the cost management plan and schedule management plan are only identified as inputs in the list of ITTOs while communications management plan and procurement management plans are identfied as both inputs AND outputs in specific processes.  Comunications and risk are not even one of the "big three" in what is considered the "triple constraint" (time, cost, scope).  This seems very inconsistent of PMI in regards to tracking and managing key management plans.  They have to originate from an output somewhere in the planning - why are they not identified as an "O" of list of ITTOs?  There must be a logical explanation for this but I do not understand why that is.  Thank you to anyone who may have an insight on this.