Agile software development

Detailed, long-term plans for major, custom software projects have long been the norm in government. But, as software engineers and policy makers have learned over the years, those plans are never correct. They need a lot of costly modifications, leading to requests for more money to pay for "change orders." It’s time for government executives and budget officials to stop asking for detailed long-term plans, and instead to budget for software projects in a new way.

Planning an entire project upfront is known as "waterfall" development. Imagine planning a month-long family vacation of driving around the United States. Under waterfall, this would entail planning up front each day’s agenda, including the route driven, booking every hotel room, pre-paying for every meal, pre-buying tickets for admission to attractions, etc. This would never work because things change, unexpected options come up, and no rational person would want to lock in every decision at the start of the journey when they don’t know what the journey holds. Instead, most people would map out the general route to be taken and plan a few major stops — the specifics would be sorted out as they progressed along the way.

"Agile software development" refers to using this trip-planning methodology for building and modernizing software systems. Instead of relying on years of costly planning and "requirements gathering" before beginning to write actual software, agile development projects are planned only in broad strokes, with a well defined description of the overall project goal and a strong preference for just getting started. A small, empowered, self-motivated team (usually 5-9 people, including developers, product managers, user researchers, writers, and/or security experts) is dedicated to accomplishing that goal, using user-centered design, working in two-week cycles to deliver some actual working software.

On day one, the team plans only what they’ll do for the next two weeks. (The length of a project’s cycles can be as brief as one week or as long as four weeks — two weeks is the most common.) Each task they’ll work on is in the form of a "user story" — a specific user need revealed by user research.4 The entire collection of user stories to be worked on is called the "backlog."

The team works on a selected group of user stories for two weeks and, at the end, the team reviews the work that they did, tests it with end users, and then plans the next two weeks by pulling more user stories from the backlog. Repeat. Each of these two-week cycles is referred to as a "sprint."

In the beginning, the software they produce may not seem like much (and may even be replaced by something else later), but it will gradually and systematically inform the project’s technical approach and help the team sensibly integrate the project into an agency’s existing legacy system.

Functioning software is delivered at the end of each sprint, without exception — fully-tested, fully-documented, ready to be used. In this way, value is delivered constantly, until the software is good enough to be rolled out for broad use. The team continues to work until they accomplish all of the goals or they run out of money, whichever happens first.5

The vendor is paid for their employees’ time, not for a software system. Everything created by the vendor — software, documentation, research, designs, everything — is owned by government, delivered to government at the end of each sprint. Technology changes, government policies change, regulations change, laws change, and leadership’s priorities change — any project that is planned in great detail up front will be unable to adapt to those changes, and will be at significant risk of failure, significant cost and deadline overruns, or costly "change orders."

By coupling agile with user-centered design, a development team can constantly iterate toward solving the needs of end users in ways that would have been impossible to learn about up front.

Earlier this year the U.S. Department of Defense’s Defense Innovation Board released its Software Acquisition and Practices (SWAP) Study including a concept paper on "Detecting Agile BS," which provides a useful synopsis of agile practices, and a series of questions to help non-technical leaders understand whether those practices are being followed.


4. A user story reads in form of "as a [role], I need [this thing], so I can [accomplish this]." For example, "as a social worker, I need case notes to be cached on my phone, so that I can access case notes in areas without mobile phone service." All technical work is done in the service of addressing a user story. ↩︎

5. Stack Overflow’s 2018 survey of 57,075 developers found that 85% of professional software developers use agile. And a 2015 study by Hewlett Packard found that "the vast majority of organizations [they] surveyed reported that today they primarily use Agile methods." The process described here is not extraordinary in any way. ↩︎