Friday, January 12, 2007

Keys to Software Development Success

After some thought and reflection I have deduced two key aspects to successful software development:

1) Focus on teamwork (lack of too many teamcide practices)
2) Use a process oriented around the integrity of the source code

The first key seems straight forward, but somehow many organizations take it for granted. The word teamcide might not be familiar to you (read Chapter 20 of Peopleware). DeMarco & Lister were attempting to write a chapter about how to make teams jell. They gave up and instead wrote a chapter on ways to prevent teamwork. It is very insightful. I have found that even when an organization goes out of its way to kill teamwork a strong leader can overcome it. First you must realize the problem before you can overcome it.

The second key aspect can be interpreted many ways. I will try to further explain myself. One of my first jobs was as a software developer for Motorola. Some VP had decided we needed to be CMM level 3 so every developer was forced to work 4 hours a week on process improvement. I was young and got involved as a capability area lead. After reaching level 2 I saw improvements and when I started a new team I carried over many of the practices that I had learned. When I look back on what worked two things come to mind:

1) Unit Testing
2) Strict control of /main in SCM

Both revolve around the concept of keeping the code in the best shape as possible. Unit testing prevented many bugs from ever being merged into main. In fact only two people could check out from main and not without running the entire suite of automated unit tests.

Jumping to present day; I work with a vendor that is struggling to produce quality code in a timely manner. When I look at their process I see no real SCM - all code is checked into main by anyone and there are no automated unit tests. All tests are GUI driven and run manually. The sad thing is they have a fairly strict process. They are not 100% compliant to it, but I bet with just a few tweaks they could achieve SEI CMM level 3 and still struggle to produce quality code in a timely manner.

Many people are caught up in the Agile craze these days. Agile is best described by the manifesto (

- Individuals and interactions over processes and tools
- Working software over comprehensive documentation
- Customer collaboration over contract negotiation
- Responding to change over following a plan

I truly believe that you could follow this manifesto and still struggle, but I find it hard to believe that you could follow my keys and struggle. I might be naive, but almost all problems I have run into in my 16 years of professional software development experience come down to poor communication or teamwork (they are extremely related) and a lack of understanding of the importance of the source code. Many processes place the same emphasis on documents as the source code. In fact many people believe the same processes that work for documents work for source code. The only tools available to written documents that I can think of are: human reviews and version control. Source code has the unique ability to be compiled and tested all without the ever erring human mind. I am not saying human review is useless, it is just insufficient.

One thing I have said little about is using iterative development versus waterfall. Part of me thinks it isn't worth saying anything as the waterfall process has been completely debunked, but some people still cling to it. I will simply say that the you can never achieve high levels of source code integrity if you start with a big ball of untested code. The waterfall process will start with such poor source code integrity that you will never be able to reach a high enough level to acvhieve success. You must start small to achieve high integrity and grow a little at a time. The human brain isn't big enough to make large leaps in source code without loosing integrity.

No comments: