Monday, May 31, 2010

Holistic view of Continuous Integration & Build (elements of CIB) – Part 2 of 9

In the last episode (e.g., 1 of 9) of this series, I introduced the topic of Continuous Integration and Build (CIB). In this episode, I will introduce the elements of CIB. The key elements involve four areas: a mindset change to thinking more continuously; the entrance criteria that makes the CIB process perform; the components to initiate an effective CIB process; and finally key infrastructure to enable the CIB process. Let us walk through these areas at a high-level.

An Agile mindset merges with the CM mindset. 
  • A very interesting cultural shift occurs when the concept of “continuous” is ingrained in the culture and method. Agile embraces a mindset of continuous change where the build process moves from an event-based integration process to a continuous integration process. In other words, no one needs to hold onto large amounts of changes for a major integration effort or declare that builds will occur nightly, weekly, even hourly.

The entrance criteria for an effective and lean continuous integration and build process include:
  • The ability to specify the right ‘bite-size’ level of story or requirements tasks that represent changes that allow for granular and frequent code changes. This implies that the Agile team can understand the stories well enough to divide them up in small and consumable tasks which allow the programmer to make changes frequently and incrementally.
The key components to initiate an effective continuous integration and build process include:
  • Right-size the branching strategy that reduces risk yet ensures code stability where people can work in a stable workspace without being impact by changes of others on a regular basis.
  • Shift in roles and responsibilities of who performs merging and building.
  • Minimize the merge process to reduce work for development
  • Emphasize building in general and understanding the build levels so it is clear who the target of the build is for. Builds can occur within a private workspace and within shared branches like the mainline or project branches.
  • Test with teeth by establishing and conducting unit testing at the individual programmer level and then smoke test after the integration build.
Underneath all of this, there is a need for infrastructure to support a continuous integration and build process. The two primary elements of this include:
  • CM version control system that has the capability of establishing the desired branching strategy, has an automated and intelligent merging capability, and can integrate with continuous integration and build tools.
  • Continuous integration and build tool that supports an automated build process. There are many continuous integration and build tools on the marketing ranging from vendor products to open source and freeware tools.
Let’s delve deeper into each area. Consider reading the next episode which focuses on the Agile and CM Mindsets (Part 3 of 9) and what this means in an Continuous Integration and Build process.

Note: If you started with this entry (Part 2), consider reading part 1, Holistic view of Continuous Integration & Build – Part 1 of 9