A number of organizations are focused on reaching the optimum level of the Capability Maturity Model (CMM), where "optimum" does not necessarily mean the highest. There are also other systems such as Carnegie-Mellon University's SEMA, or particular ISO standards.
Small software companies will sometimes use less formalized approaches. Each organization works out its own style, which lies somewhere between total technocracy (where all is defined by numbers) and total anarchy (where there are no numbers at all).
Whichever way the organization goes, they consider the pyramid describing the cost and risk of introducing change to already-begun development processes: