The main problem when using network drive for collaborative design by multiple people is:
Need to be always in touch with other. For example, you added several new parts in main assembly ("A" and "B") and saved it to server. At the same time, your colleague add to its copy of the main assembly another one new part - "C". This copy of assembly don't have your two parts. If the colleague save this assembly to the server, then the assembly will overwritten and will have only new part "C". This is a problem. All your work will be lost. For this case, for example, the PDM systems make the CAD document read only for others, when somebody opens it for editing.
Collaboration on the one assembly by several people is possible if you will use the technique top-down design, like skeleton models or master model.
In short, you create the main assembly as a template. Using sketches, points, axis, etc you mark the key dimensions of your design. Then spread, for example, copying the individual elements in a part or subassembly. And everyone works only with their files, filling their geometry.
http://grabcad.com/questions/top-down-asse...in-pro-engineer
http://www.cad-notes.com/master-skeleton/
http://www.mcadcentral.com/creo-tips-trick...t-n-models.html