Beyond Continuous Build: Shortening the Development and Test Feedback Loop


The author walks you through the details of actually implementing a continuous quality automation infrastructure. He builds up an example that addresses both the key principles and feedback cycles.

A key part of Agile development is the retrospective process. A good way to uncover your current feedback cycles and find a starting point is to hold an automation-focused retrospective. Gather the team and brainstorm about what currently works well, what things you would like to do differently, and areas where you want to increase your level of automation. From this meeting, generate a ranked backlog of stories related to automation that you would like to address. Then, mix in items from this list with the product backlog to balance advancing the product along with advancing the internal infrastructure.

If the business or your Product Owner is skeptical about the value of automation, add in a few small stories with the biggest bang and be sure to demonstrate their value during the iteration demos. Finally, as a last resort, if the business or your Product Owner is completely unwilling to consider investing time in the infrastructure necessary to deliver faster with higher quality, the team can work on areas of automation as a flat tax applied to the estimate of each story in the product backlog. This isn't a healthy dynamic, but as you generate small wins it will help you reinforce the benefits of the improvements in quality and speed you're generating.

As a reminder of the feedback cycles and Lean thinking covered in Part 1 of this article, below is a picture of the development cycle. In this development cycle, all the batching and queuing has been removed, and quality feedback is being generated at the code level, at the automated functional testing level, and at the manual regression level.  


Unit Tests amp; Code Metrics

 Unit tests and code metrics are a good place to begin our example. By implementing continuous integration (where the code is built and the unit tests run on a dedicated, non-developer workstation), you are most of the way toward having feedback loops at the code level. This level of automation starts by finding a dedicated machine to execute the build. How many times have you successfully compiled your code, checked it in and later discovered that the code in the repository wouldn't compile for anyone else because you forgot to add a file? By having a non-development workstation for builds, you will get feedback about the quality of the code in the repository, not the quality of the code on your machine.

Next, you will want to focus on scripting the build process. If you are developing in Java, you're probably familiar with Apache's Ant project. Ant [] and its .Net derivative NAnt [] use an XML-based declarative language to describe, and ultimately execute, the build process. Ant isn't only for Java projects; I once used Ant to drive the build process of a project that was written in five different languages on two different platforms. Some people still prefer to use make or shell scripts to drive a build, but there are many higher-level tools that are just as powerful, and whose scripts are much easier to maintain.

Ultimately what you want is one thing to execute that will kick off your build and produce all the necessary build artifacts. Maven [] is a build environment that is sophisticated enough to manage all the project dependencies, manage the build process, and create a project home page complete with documentation. Maven is a powerful tool, but it does impose its conventions on your build structure and process. If you can accept those conventions, it can be a very powerful tool in your automation infrastructure. Whatever


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