Symptom [internal staff functions only]: Clients would rather do the organization's work themselves than buy from the organization (i.e., pressure for decentralization).
For staff functions within companies, decentralization means that people within the client community are doing the work of the organization rather than "buying" from the central staff function. It may take the form of clients starting their own groups in competition with the organization. Or it may be just a series of isolated cases of clients hiring external contractors to do work that could have been done by corporate staff. Loss of market share could even manifest as clients doing the work of the organization themselves, often without proper training and tools.
There are a variety of reasons why internal clients would rather not work through a corporate staff function. They fall in two categories: control, and partnership.