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…which stands for “you ain’t gonna need it” and is an important principle of Agile development, with strong benefits for the business.

The basis for YAGNI stems from a failure common in many software development projects: that when a developer creates a component of a system they tend to give it more flexibility than is immediately necessary, so that it can be reused in more contexts and provide more value. But the result in practice is almost always over-engineering: the component costs more to develop, the suspected additional use rarely materialises, when it does materialise it has requirements that don’t quite match the actual implementation, and the component as a whole is more brittle, less comprehensible to successive developers and more difficult to maintain.

By contrast YAGNI says “you ain’t gonna need it”: develop the absolute minimum to get it working for the immediate problem, and extend it later only if another specific needs arises. This works in Agile development because there is a wider supporting structure which enables changes to be made with minimal cost.

An excellent example of YAGNI in action was our implementation of content workflow. There are lots of things you could do with workflow. You can lock content to ensure that only one person can edit it at a time; you can branch content so that different versions can be worked on simultaneously; one of our senior stakeholders was keen on allowing numbered versions which she had seen elsewhere, allowing individual changes to be tracked and traced, and even allowing someone to switch back to a previous numbered version — but she did say that the feature was almost never used.

What we did in practice was a minimal workflow with minimal cost: we built in the ability to have content as draft and live, and very little more. That was sufficient for the staff who we knew would be using it. It seems like we could have taken the opportunity to build more, in case more people with more needs would use it. But you know what they say — you ain’t gonna need it. In the months following that very early stage in the project the company changed a lot, and among other things this included much more integrated working between editorial teams who were previously designated “web” or “print”… these days that distinction has diminished. The technological impact is that many editorial staff are using an integrated front-end, sitting outside the web system, and that’s where the workflow is handled now.

The industry-wide drive for integrated publishing changed our working environment; if we’d have developed elaborate workflow in the web system it would have been wasted effort, and a large wasted cost for the company.

…which was a size of problem we noted but wouldn’t tackle.

When we estimated the work for R2 up front we used t-shirt sizes for each feature: S, M, L and XL. The largest single task the team would tackle was an L, which was the equivalent of five days’ work. We felt this was a good maximum for two reasons: first, it delivered something of value within a reasonable space of time and what should have been one iteration; second, if we could imagine developing it within five days then it was probably sufficiently understood, whereas anything bigger risked being too complex to estimate without a lot more thought.

However, during the time-limited initial planning period we were required to estimate things that needed more analysis than we had time for. These features we labelled XL and gave a nominal equivalent size to: 10 days’ work.

However, we would never actually start a task that was labelled XL. We would always break it down before the event into smaller parts. The aim was that although individual estimates might be over or under, on average they should balance out and the total size of the project should remain constant.

Of course, for XL tasks it was quite possible that a more thoughtful estimate would produce a total that was far too big to be able to be balanced out by other tasks. In these cases we would have to reconsider our options and think about dealing with the problem in a different way — most likely by having a less comprehensive solution. However that didn’t tend to be too much of a problem. In many cases by the time we got to the XL task our stakeholders’ needs and priorities had changed so much that there were a lot of new options and directions that people wanted to explore, and ones that they would not have thought of in those very early planning stages.

This is an example of why planning was important, but very detailed planning would actually have been quite wasteful.

…which was a semi-regular event of Wii tennis in the office, but a very useful part of our R2 work, too.

Each launch required a small army of technologists to be on-hand: to run the various scripts, check the results, and deal with any problems that might arise. We needed to arrange these teams carefully because launches happened overnight, so we’d need an overnight team and another team in early the next day to pick up any remaining issues.

All this was fine, but after a while someone realised we’d missed a trick. I think he actually wanted to be part of the overnight team (it’s always exciting to see these thngs go live) but wasn’t actually on it. So he arranged with others to bring in some games consoles, and wired one up to a big screen, the others to projectors. It was a big draw, and a great way to have an extra group of techies staying late in case the need arose.

Still, we couldn’t be cavalier with this. For example, we made sure the gamers were located far from the launch team — the launch team had a serious job to do and didn’t need distraction. But that didn’t prevent the benefits: every so often a gamer would slip out of Guitar Hero and wander over to the launch team to check up on progress, offering some advice and support if necessary. One time a critical SQL script was running worryingly slowly and a call came through to see if someone could contribute to the investigation; a couple sat down at a machine a few feet from the Mario Kart players, traced the problem, and suggested a change to the script which was agreed and did the job. That night it made the difference between “go” and “abort”.

If there’s a general lesson to be drawn from this I don’t think it’s to keep a Wii console in the stationery cupboard along with the paperclips and envelopes. But exploiting opportunities that are specific your particular situation is probably a good thing to do, even if they aren’t enshrined in official company policy.