My have raised the question in part 1 and ask readers what they think about the manager's situation. My answer is rather simple and I do think in some cases, members think the wrong way on testing. All know that we have many kinds of testing: functional, integration, performance, unit testing etc. Each type is done by some members, may be it is done by whom implement feature or someone else, may be it is executed by others. In software industry we have two terms verification and validation. Verification means build the right thing and validation is build the thing right. Mostly verification activities belong to functional testing and it needs someone takes user role to verify the product to see whether that product meets client's expectation. It is not be done by developer himself but someone else (I avoid to use QC here, you will know the reason later). It is better done by the BA or the best case is client involve deeply to project and validate whether team do right or wrong. But BA number is limited also requiring user involve deeply is a illusion, so we need to have third-party side can play the user role and we have the team names QC. In fact, the major activities of QC team is making sure the quality of product meet client's expectation not creating test cases, test procedures etc they are only the tools help QC team to meet that goal also we do not need QC think out-side what developers, BA can not think because it is not a requirement to QC team and it is depended by each member's capacity.

In part 1, developer has wrong argument on testing type, he thinks that unit test can cover integration and functional testing but it is not correct. We have only two types of defect caused by developer team, they are:
1. Lack of unit test, they can not cover all cases of testing. In almost cases, I can say defects occur by Null Pointer or Wrong Format are lack of unit test.
2. They understand the requirement wrongly.

The developer's responsibility is making sure they perform unit test very well, it is not the major responsibility of QC is catch up defect for developers by lacking of unit test. The major responsibility of QC team is verifying whether the developer understand requirements and implement correctly. It does not mean the QC is expert than developer in requirements and system. If some defect is posted to DMS (Defect management system), it does not mean developer team do the wrong thing but it means the developer and "simulated" user (QC member) understand the system in different ways. Such defect is correct or not it is depended on the argument between them with the involvement of BA and client if needed.

For each project, the difficulty of functional testing is different. If project is just a e-learning website, it is rather easy to play the end user role but if your project is a development framework the skill of QC sometimes require more than developer skill, especially if QC team is required using gray box testing. So, the thinking that QC member is un-skilled guys that is not un-fair and un-practiced assessment.

So my answer is we all need to have QC team in any projects but you understand their responsibility clearly, developer has his job and QC has his job and they are different. The skill-set for each roles are different too, so just be professional and support other sides during developing software is the good way instead to have the wrong perception to QC team.