In the 20th century organizations viewed software development investments as projects. They would plan the project, document the requirements, implement the software, test the software, then release the software. While this process made sense on the surface, a lot of the software that it produced failed miserably after it was released. Processes that follow this development model are now labeled Waterfall.
In the early 21st century there was a great shift in enterprise software development. In February 2001 a group of 17 leading software engineering experts met at a ski lodge in Utah to discuss the state of software development. What emerged from that meeting is called the Agile Manifesto.
We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value:
Individuals and interactions over processes and tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan
That is, while there is value in the items on the right, we value the items on the left more.
The agile manifesto was an important first step in shifting the mindset of software development from a project mindset to a people and organization mindset.
In 2002 Ken Schwabler and Mike Beedle, two of the signers of the Agile Manifesto, published the book Agile Software Development with Scrum. This book defined the processes most commonly used by Enterprises that adopt agile software development. The process below shows a high-level overview of the scrum process. In this process teams begin with a product backlog containing a prioritized list of features. The team has a sprint planning meeting to determine work to be done for the next release and created the sprint backlog. The scrum team then begins implementing the features, meeting each day to have a daily scrum meeting. At the end of the sprint the team holds a sprint review and sprint retrospective to review their output and discuss practices that they could use to improve future output. The team then returns to sprint planning and the working software is released.
A high level overview of the scrum process.
Agile and Scrum are deep topics and a detailed analysis of Agile and Scrum are beyond the scope of this paper. Readers who are not familiar with agile should start with the book Agile Software Development with Scrum but should also continue their research and training to learn the depth of principles and potential practices that Agile and Scrum have to offer.
Over the nearly two decades since this book was released many organizations have adopted and evolved some type of scrum process. Organizations that simply followed the process continued to struggle getting value out of the software that they developed, but organizations that shifted their focus from the software itself to the people and organizations that the software was developed for began to see great benefits of this approach.
For the purposes of this paper I will highlight a few key areas of Agile vs. Waterfall.
- Agile software is released frequently. Typical enterprise software developed in an agile environment is released once or twice a month. Some organizations are moving to a continuous deployment model where small features are released as soon as they are verified, shortening the cycle even further. Each of these releases is viewed as an incomplete but usable version of the software. As more features are added the usability improves, and the feedback from earlier releases is incorporated into future releases. In Waterfall the product is not released until all features are complete. This leads to long release cycles, typically ranging from six months to two years.
- Agile software development requires interaction with the business throughout development. Organizations have many models for achieving this. At Chatham financial we use Product Owners who report to the business but work full time with the development teams to represent the needs and priorities of the business. In a waterfall model, business analysts finalize requirements before development begins, and the development teams have very little business interaction beyond that point.
- Agile software development is iterative. Each release is built on the previous release and changes are small and incremental. Waterfall software may have multiple versions, but each version is a major project that lives through a full project lifecycle.
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