Messages do not happen spontaneously, they are the result of multiple stages. This is true of any message, whether in advertising, product development, election or public interest campaigning. This is true for print, broadcast, new media or any other form of dissemination.
The Communications Supply Chain, at its best, begins with a need, a stimulus or a reason to communicate. It then goes through the decision making process, creative development, production or manufacturing and ultimately dissemination. It can be short, with just two or three stages or it can be extremely complex with multiple stages involving staff, subcontractors, suppliers and stakeholders.
The Communications Supply Chain is often inefficient. This is not always the fault of those involved in the process. Sometimes a lack of resources cause it to malfunction. If you underfund or under-support a process, it can understandably suffer.