For more than a decade, software teams have benefited from agile development methods. They have adopted incremental development practices where solutions evolve through collaborative development. In this article, I will explain what Continuous Integration is and describe some of its benefits.
What Is Continuous Integration?
Continuous integration (CI) was created for agile development. It organizes development into functional user stories. These user stories are put into smaller groups of work called Sprints. The idea of Continuous Integration is to find issues quickly, giving each developer feedback on their work. TDD evaluates that work quickly. With TDD, you build the test and then develop functionality until the code passes the test. Each time you make a new addition to the code, its test can be added to the suite of tests that are run when you build the integrated work. This ensures that new additions don’t break the functioning work that came before them, and developers whose code does in fact “break the build” can be notified quickly.
Agile methods allow software and systems teams to respond quickly to changes. Continuous Integration helps systems development teams be agile and respond to rapid business changes while at the same time ensuring that the actual hardware and software under development are in constant sync. CI allows team members to work effectively in their domain groups, focused on the tasks that they’re best at accomplishing. At the end of each day, they know that their contributions to the project are integrated and that the component parts work together. If something doesn’t integrate, it’s quickly discovered.
From a technical perspective, Continuous Integration helps teams work more efficiently. These teams can be cross-functional or geographically distributed because the constant integration work will ensure that you don’t get deviating designs. People can work on a large team because the different components of a complex system will more assuredly work together. It solves many of the early pitfalls that these nontraditional agile teams might have experienced without CI. Combining Continuous Integration with test-driven development puts more people under the agile umbrella because it allows agile methods to work more efficiently.
Continuous Integration is a software development practice where members of a team integrate their work frequently. Usually, each person integrates at least daily, leading to multiple integrations per day. Each integration is verified by an automated build (including test) to detect integration errors as quickly as possible. Many teams find that this approach leads to significantly reduced integration problems and allows a team to develop cohesive software more rapidly.
The goal of Continuous Integration is to provide rapid feedback so that if a defect is introduced into the code base, it can be identified and corrected as soon as possible. Continuous Integration software tools can be used to automate the testing and build a document trail.
What Are the Benefits of Continuous Integration?
CI prevents integration problems. Integration bugs are detected early and are easy to track down due to small change sets. This saves both time and money over the lifespan of a project. It also helps avoid last-minute chaos at release dates when everyone tries to check in their slightly incompatible versions. Instead, everyone is committing code frequently.
Continuous Integration categorizes developer tests. It uses a dedicated integration build machine as well as continuous feedback mechanisms. It also allows for better build staging.
When unit tests fail or a bug emerges, if developers need to revert the codebase to a bug-free state without debugging, only a small number of changes are lost because integration happens frequently. There's a constant availability of a “current” build for testing, demo, or release purposes. Frequent code check-ins push developers to create modular, less complex code.
CI enforces a discipline of frequent automated testing. It also invites immediate feedback on the system-wide impact of local changes.
Metrics generated from automated testing and CI (such as metrics for code coverage, code complexity, and features complete) focus developers on developing functional, quality code, and help develop momentum in a team. Software builds are separate from software deployments.
Additionally, with CI, you can say goodbye to long and tense integrations and increase visibility which enables greater communication. You also spend less time debugging and more time adding features.
CI means automating the build, automating deployment, and making your build self-testing.
Overall, CI allows you to proceed with confidence that you’re building on a solid foundation. It reduces integration problems, allowing you to deliver software more rapidly. Continuous Integration is quality assurance.
From a business perspective, there are many benefits to Continuous Integration. It offers better business results and can bring products to market faster by finding issues when they are young and small instead of making you wait until they are large and more difficult to fix. CI also lets you respond better to requirements that are introduced while the product is being development. This creates a better product for the customer, which is the real promise of agility.