What does the stability of a company's net profits depend on?

Why can a direct link not be drawn between an increase in production costs and the corresponding drop in profits?

Should you discount even if there is no inflation and no risk? Why?

The main manufacturers of telephony equipment (Ericsson, Nokia, etc.) provided telecoms operators (Deutsche Telekom, Swisscom, etc.) with substantial supplier credit lines in order to assist them in financing the construction of their UMTS networks. State your views.

An aeronautics group has substantial inventories of unfinished goods. What consequences will this have? What measures would you suggest to improve this situation?