Who Owns Quality? Part 2

Developers must take ownership of testing their code for functionality, integration and performance

Let us examine the consequences of “Developers Own Quality”.

Quality is already in the code at the time when it is delivered to the QA team

In other words, the code meets all functionality and performance objectives.  The obvious consequence – as suggested by Extreme Programming (XP), and Agile Software Development – is that, in addition to writing code, developers must also test it. More importantly, developers own the results of these tests.

Too often, I have heard developers claim that their task was complete once they had provided Unit Tests along with their code. Writing unit tests is a good thing, it is an important and necessary step, but it is far from sufficient. Rather, developers must take a results-oriented approach to testing, and ask themselves: do my tests PROVE that my code works?

Beyond a comprehensive suite of unit tests, which validate basic operation of the code, two main areas must be addressed: (a) integration and (b) performance.

Integration testing leads us to another XP and Agile best practice: frequent integration releases (or milestones) to ensure that all newly contributed code plays well together. For example, two developers will have often a different interpretation of an API. While each may have done the right thing in their own mind, and pass their individually created tests, the code, once integrated, will not work.

So, why ask developers, rather than QA, to test integration and performance? It is simply a matter of efficiency.

The process of releasing code to QA, having QA set up their test environments, find a bug, make sure it really is a bug, file a bug, assign the bug, re-run the test for the developer, wait for the fix, verify the fix, verify that the fix did not break anything else that worked before, and finally close the bug, is just too long a process. It should only occur in exceptional circumstances, or in controlled situations (more later).

To me it is also a matter of pride. As a developer, I need to be confident that I deliver solid work-product to my teammates. Finding a serious bug in my code (whether functional, or performance), once I have released it, should be a major embarrassment. I often tell my team – jokingly – “If QA finds a Severity 1 or 2 bug in your code, you owe me fifty bucks!”, as an illustration of the level of confidence and pride that one should have in one’s code.

In summary, comprehensive testing, is part and parcel of development. A developer who is proud of his/her code, and proves that it meets all functional, integration and performance requirements, is not only an efficient developer, but someone who makes his/her whole team efficient.

About Software Engineering – from the Trenches

Software Engineering applies a holistic optimization to all the tasks, beyond coding and testing, involved in creating a software product

“Software Engineering – from the Trenches” chronicles what it takes to create a software product — in real life.

“Software Engineering – from the Trenches” is not only about “software development”; writing code is only one task – necessary, but not sufficient, to build a product. We will also discuss requirements, architecture, design, testing, release management, documentation, deployment, and support. One of the main themes in this blog is that Engineering is holistic and encompasses all these critical activities which, whether we like it or not, consume the time of each software engineer. One of our main goals is thus to approach product creation with a methodology that is optimized across all these activities. For example, while iterative development methodologies (XP and agile software development among them) are quite popular, we will advocate for, and justify, strong and detailed upfront design.

Before jumping into the fray of software methodology, our first series of blogs will focus on the roles of responsibilities of the different actors in Software Engineering: developers and testers of course, but also, product manager, release manager, consulting engineers, etc. Before examining team-level strategies, we need to first agree on everyone’s scope of responsibilities and mutual expectations. We each need to understand our, and each other’s,  job description before we crack open the playbook. Surprisingly enough, controversy has erupted whenever I have broached this topic with my team at each company where I have worked.

This blog is for you if … you are a software engineer, QA engineer, support engineer, product manager, release/project manager, software architect, lead,  director, VP, or CEO.  Anyone who is attempting to understand the mistery of software creation, anyone whose day job (and/or night job) involves software will benefit from this blog and will learn road-tested techniques to reduce stress, increase predictability and stimulate innovation.