Pipeline for web app development projects

One way that seems to work is to have a pipeline constructed as:

1. Requirements team go out to the customer/organisation to try and get decisions on what problems actually need to be solved and any fixed requirements/specification.
2. Once the requirements are firmed up the QA and developer join. The QA to understand the nature of the problem and record how to test if the problem is solved. The developer to understand the problem and start thinking about possible solutions.
3. QA/Dev can raise questions to requirements team to clarify specification (if required).
4. Once QA/Dev understood the requirements, QA then will write final acceptance criteria (to test if the problem is solved)
5. The problem can only enter a sprint when the QA and developer agree that it is ready to start.
6. Within the sprint the developer and QA negotiate an acceptable solution. The customer must be kept informed of changes.

At all stages any agreements with the customer must be record in the bug database.