Continuous delivery software is developed to allow the software to be released to production whenever release is desired. Thus, the software can easily and quickly be deployed at any point during its lifecycle. Before delving further into an explanation of what continuous delivery software is, it might be helpful to explain what it is not as well as review the pitfalls of traditional development and define certain terms.
Definition of Terms
The traditional method of software development is referred to as the waterfall approach. Under this method, all specifications are established at the onset of the project. Development proceeds in a linear fashion with the final build, testing, debugging and deployment at the end of the project. If the business goals, market conditions or technologies change during the project, it is difficult or impossible to make mid course corrections without substantial delays or significant costs. Furthermore, businesses realize no return on investment until the product is deployed. Although the waterfall method is often ideal for a small project that can be completed and deployed quickly, a large project may require one to two years between project initiation and deployment. To counter the pitfalls of the waterfall approach, the agile method was introduced.
Agile methods for software development breaks large projects into a number of smaller tasks that can be completed independently. Specific features can be prioritized to enable incremental releases that can be deployed independently, allowing the company to start realizing a return on investment. Mid-course corrections or adding new functionality can be accomplished more easily and at less cost than would be possible under the waterfall method. Development takes place in cycles that normally last less than two weeks. As the cycle draws to a close, the build, testing and debugging takes place, after which the module can be deployed.
Continuous delivery embraces many of the principles of agile methods, but the two should not be confused. Agile methodology does not ensure that the software could be released at any time with little effort, and it does not require continuous integration.
One of the guiding principles of continuous integration is that all components necessary to build the software are kept in a single location. When developers need to work on the project, they "check out" a copy and perform their tasks. After debugging and testing, they integrate their work with the master copy. Automated tests verify that no conflicts exist at that point. Typically, additional testing is performed after the integration to ensure that the software is still "bug-free" after the update.
Without continuous integration, software cannot be readily deployable at all times. Therefore, continuous integration is one of the major requirements for developing continuous delivery software.
What are the common qualities that define continuous delivery software?
Continuous delivery software is not limited to a specific type of application, deployment scenario or user base. The concept can be applied to virtually any development project, regardless of business philosophy, industry or environment. However, all software developed under the principle of continuous delivery share certain qualities.
The software (not just individual features) can be deployed throughout its lifecycle. Deployment becomes a "non-event" rather than a major challenge.
All components of the software are visible to every developer at any time. All developers can retrieve the software and review changes independently with a high degree of confidence that they are working with the most current version.
Automated acceptance procedures allow the code to be largely self-testing. Problems can be detected upon integration, allowing easier debugging and corrections.
Integration, testing and debugging are continuous. Unlike the cycles involved in "pure" agile development, these tasks are normally performed on at least a daily basis and often occur multiple times each day.
New versions are quickly pushed to production or an environment that mimics production. This allows constant testing to ensure that the software functions as desired in a production environment.
Every possible process in the delivery pipeline is automated. This allows faster deployments as well as ensuring that critical tasks have not been overlooked.
Developers work in a collaborative environment. Every developer's work is visible to every other developer, allowing potential conflicts between tasks to be identified and resolved before they impact the functionality of the software.
Continuous delivery software is deployed to actual users on a frequent basis. Users can provide feedback, request modifications or notify developers of issues to make changes less of a burden.
What are the major benefits of continuous delivery software for my business?
Continuous delivery software offers several important benefits in addition to making tasks easier for the developers. Continuous delivery can also provide a number of benefits for the organization as a whole.
Deployments become less risky. There is always an element of risk involved in a software deployment. Users react negatively to bugs, and the longer it takes to fix them, the angrier users may become. By deploying after every small change, it is easier to identify and fix bugs than it is if deployment is held until the end of the project or the end of a cycle.
It is easier to build a truly useful product. Defining detailed specifications at the start of a project can be difficult. There is always the chance that users forgot to include a crucial detail, or that when they see the software in action, they realize they actually wanted a feature to work differently. Continuous delivery allows real users to interact with the software to perform real tasks. Users can then provide feedback quickly to allow developers to incorporate changes or correct the specifications.
Progress is easier to track. On a major project, the business may not receive a tangible product for many weeks or even months. Often, business managers must rely on statements from the project manager or developers regarding time remaining until deployment or the percent of the project completed. With continuous delivery, updated versions are deployed frequently, allowing business manager to see a tangible product in actual use.
Deployments are easy to push or withhold. Deploying the new version is often as simple as "pushing one button" to send it to all users. However, deployment can be withheld if management desires to do so, or new versions can be deployed to only certain groups of users.
Continuous delivery can provide cost savings. In many instances, it is more costly to deploy a software "in full" than in a constant series of deployments. If there are bugs, it can take a significant amount of time and resources to find and correct all of them. Adding functionality or features "after the fact" is normally more expensive than incorporating them during initial development. Furthermore, users can be receiving the latest versions immediately, which can be a cost savings if one of the goals of the software is to improve efficiency.
Once, it was acceptable to wait months for a new software. In today's world, however, technology is changing rapidly — and so is the market. Continuous delivery offers the ability to respond to these changes quickly and in a cost-effective manner, allowing developers to deliver useful, reliable products with less delay.
Can I use continuous delivery in an outsourced software development environment?
Sure you can! Continuous delivery also requires a continuous flow of communication between your company and your outsourced software development team. You can contact us directly to discuss how our U.S. based project managers help facilitate that in an efficient and effective manner.