At this point in time, the cycle for creating a development process has been laid out. The missing element in this process is the full role of QC/QA. In short the role of QC/QA is to ensure that each phase of the process is fully vetted and completed. With this in mind QA/QC's roles in the development process as a whole come down to.
Idea Phase: Primary role here is to ensure that all ideas are captured and those captured ideas are categorized as far as "must have" and "would like to have" are concerned.
Design Phase: QC/QA is responsible to see that all documents due from this phase are completed and that they match. Match meaning anything UI design creates must include all requested features from Marketing and Engineering. QC/QA is responsible for vetting the resulting Marketing Spec. to ensure that it is complete, clear, and in line with what was decided. Since this document is probably going to be written outside of the meeting(s) where the decisions are made it is important that all aspects are completely captured.
Engineering Phase: QC/QA is responsible for ensuring that the Engineering Spec. Meets all requirements laid out by UI and Marketing. If an aspect of the design cannot be met it is QC/QA's responsibility to "clear" that change with earlier documents, see that they get amended so that all documents match in scope and features, before it is handed to the Engineering teams for creation.
Coding Phase: This is where initial QC/QA begin in a more traditional respect. Each module created must be given a check to ensure that that module is doing what it should do. That it is written in the correct language and that the code created is in a maintainable form. (Nothing can make the future worse than having to dive into old code because of a severe customer need only to find that it is not up to coding conventions, undocumented and cryptic in it's use of variable names.) At this point QC/QA should also be assisting the developers in choosing and/or creating viable tests for their module. These tests then can become tools for QC/QA to use in the final phase.
Build Phase: QC/QA is responsible for ensuring that the build master has what he/she needs to complete the task at hand and assists the build master if needed in filing concise, cogent, bug reports.
QC/QA Phase: This is the phase most people think of when speaking of QC/QA. Here the duties of QC/QA are fairly well know and don't need embellishment.