Thanks to a detailed description of the problem through 5W + 2H, we get a more detailed representation of it in comparison with the original (http://www.xmind.net/m/fcnd).
Regression testing (main scenarios) is carried out in the end of 14 iteration (before the release), a large number of regression bugs with high priority and severity lead to delay in product release, because the basic customers scenarios do not work correctly.
For Root Cause Analysis we use the Ishikawa diagram (Fish Bone) and "5 Why " method.
Lead a brainstorming session and identify all the possible causes of the problem. Answer by question: Why did it happen? For all possible causes you can use most deeper analyse.
The maine aim: to find root course and further solution.
Note: do not find a guilty person and we try to find problems in process.
After all possible reasons were considered, you need to prioritize hight likely causes for next analyse ("5 Why " method)
We decided: Testers do not have feedback from developers
MAN
There is not enough knowledge in the business area
There is not enough qualification in testing / analysis / development
Many distractions
Low motivation
Blurred vision
Non-constructive perception of criticism
Inattention to the details of functional implementation specified in the US
Management
We misjudged the time for the US implementation
US priority was estimated wrong
Risks were estimated wrong
Method
There are no acceptance test cases for US
No atomic tasks for programmers for US
The procedure for working with requirements is not clear
Acceptance test cases were not passed
Different understanding of US contents
Features depend on services implemented by other teams in other projects
There is no formalized US transfer procedure: from developer to tester
Insufficient preparation for iteration planning
US are changed during sprint
Lack of prototyping the interface
Testers do not have feedback from developers
Environment
Some external programs block our software
The required versions of the required software are not installed
Iterations with related groups are not synchronized
Ploblems with servers
Mashine
Required software were not available
Errors with a project build in CI
Materials
The US description is not atomic
Conflict new and existing features (Product was started with another Team)
Iteration changes caused significant changes in the bases scenarios
The functionality implemented in the early iterations does not correspond to the stakeholder requremetns
Changes in implementation not approved in the JS and TK after the sending of the functional to the development