Agile SCM: Basics for Small Teams

Communication is more complex with larger groups of people. Small teams have an advantage of being aware of what each person is doing and of sharing product vision. Small teams, being small, are also resource constrained, so it's important to maximize time spent delivering value and to also minimize the time spent on process overhead.

The Short Lists
Given the time constraints of small teams, we will be brief and group the general priorities of essential items for success with SCM in tools and processes.
   
Really Basic SCM
These items might seem too basic to mention, but we would be remiss not to mention them:

•    Use a version management system (SCM Repository) as the only way you share code. There is no excuse for sharing code any other way. An SCM system gives the ability to track changes and have a central place to backup and recover the business asset that is your code.

•    Create a process that enables one to get a workspace up and running quickly. A new person joining the team should be able to start with a set of tools, check out source code, run the application, and make a change on their first day. This will also make your deployment model more robust.

•    Use a continuous integration (CI) environment. Having your code in a repository is good, but only in the sense that it is usable by others when they check out the code. A CI environment gives a sanity check that your source code builds, which is the minimal criteria for it being usable. Also, enabling a CI environment means that you need to have a build process that is somewhat portable and consistent.

Keeping Things Working
This basic list will allow effective collaboration and quick delivery of features, but you may still find yourself stumbling unless some practices are added to eliminate distractions:

•    Create automated tests and run them as part of your build. Compiling, while necessary, is not sufficient for keeping code working. Automated testing adds time, but will pay off with added robustness of code and the ability to make changes reliably.

•    Work from a single code line to begin. Branch only once you have a delivered codeline to maintain that you expect is stable. Each branch is a parallel line of development and parallel work means a distraction from your main work.

•    Deploy often. The real test of whether your SCM process is helping to deliver your product is how effectively it can deploy. Don't wait until the end of a release to think about deployment practices. Start deploying your application on the first day, as this guards against problems being discovered late in the process.

•    Automate your deployments. The more automated your process is, the easier it is to deploy more frequently. This becomes a virtuous cycle (of positive feedback).

Trace and Improve
The previous lists will get you most of the technical issues, but there are still things you can do to improve how you collaborate.

•    Identify your commits with meaningful messages. Be explicit about the reason for a change in terms of business goals. Keep your commits consistent and cohesive.  Avoid mixing changes to refactor existing code that don’t alter the functionality with changes to add new functionality - split those into separate commits. If you use an issue tracking system, associate each commit with an issue number. Otherwise, refer to a feature or user story. While the code can often speak for itself, context is helpful.

•    Think and review. Since every team is different, and teams themselves change over time, it's important to review how you are working and to figure out which practices are working for you. Retrospectives are a key agile development practice, but they aren't just for agile developers. Periodically make a list of the things about your SCM and release processes that seem to be working well.  Also, review any aspects that might need improvement.

Recap and Resources
In an ideal world you would do everything on this list on day one.  Since this might not be practical,  the list is broken into parts.  To learn more, here are some resources we like:

•    Practices to use for small team SCM and their rationale:  SCM Patterns Book (Berczuk, S. P. and B. Appleton, 2003). Software Configuration Management Patterns:  Effective Teamwork, Practical Integration. (Boston, Addison-Wesley.)

•    Deployment: (Jez Humble's book) Humble, J. and D. Farley (2010). Continuous Delivery:  Reliable Software Releases through Build, Test, and Deployment Automation. (Upper Saddle River, NJ, Addison-Wesley).

•    Retrospectives: Agile Project Retrospectives. Derby, E. and D. Larsen (2006). Agile Retrospectives: Making Good Teams Great. (Raleigh, NC, Pragmatic Bookshelf).

•    Unit Testing: XUnit Patterns (Meszaros, G., 2007). xUnit test patterns :   Refactoring Test Code. (Upper Saddle River, NJ, Addison-Wesley.)

•    CI Practices and Approaches: Continuous Integration. (Duvall, P. M., S. Matyas, et al., 2007). Continuous Integration:  Improving Software Quality and Reducing Risk. (Upper Saddle River, NJ, Addison-Wesley.)

Some of these books overlap in content a bit, but an assortment of practices is necessary to effectively collaborate. On a small team one has the advantage of easier communication.  It’s important to use this to your advantage to simplify the process without underestimating its’ value in making communication easier.