How can new Software QA processes be introduced in an existing organization?

• A lot depends on the size of the organization and the risks involved. For large organizations with high-risk (in terms of lives or property) projects, serious management buy-in is required and a formalized QA process is necessary.
• Where the risk is lower, management and organizational buy-in and QA implementation may be a slower, step-at-a-time process. QA processes should be balanced with productivity so as to keep bureaucracy from getting out of hand.
  For small groups or projects, a more ad-hoc process may be appropriate, depending on the type of customers and projects. A lot will depend on team leads or managers, feedback to developers, and ensuring adequate communications among customers, managers, developers, and testers.
• The most value for effort will often be in (a) requirements management processes, with a goal of clear, complete, testable requirement specifications embodied in requirements or design documentation, or in 'agile'-type environments extensive continuous coordination with end-users, (b) design inspections and code inspections, and (c) post-mortems/retrospectives.
• Other possibilities include incremental self-managed team approaches such as 'Kaizen' methods of continuous process improvement, the Deming-Shewhart Plan-Do-Check-Act cycle, and others. Also see 'How can QA processes be implemented without reducing productivity?'.