Orcad issue while designing schematics
OrCAD does have a feature for automatically assigning designators in a hierarchical design.

Suppose, your design has following schematics (folders):


Schematic1 has components C1 and R1
Schematic2 also has components designated C1 and R1
Schematic3 is a Top Block Diagram.  It's set as a root.  It's highest in the hierarchy.  Hierarchical blocks for Schematic1 and Schematic2 are drawn on Schematic3.  If some schematic is not drawn in the root*, then it's not in the hierarchy and OrCAD will not treat it as a part of the design.


*  Or in one of the root's children.  It's recursive.  You get the idea.

Here are the steps for automatically assigning incremental designators:


Bring up the design window
In the design tree, click on the design itself.  (It's the node, which contains all of the schematics.)
Menu: Tools -> Annotate...
Select  Reset all part references to "?"
Click OK.
Open Schematic1 and Schematic2.  Notice that designators became C? and R?.  Go back to the design tree.
Again, menu: Tools -> Annotate... 
Select  Incremental Reference Update
Click OK.
You should have incremental designators throughout the design.