Productivity = throughput and cycle time

This article is cross posted from the 7digital Blogs From the Geeks:

I see lots of articles and discussions on how you measure the productivity of a development team. Having worked with cycle time and throughput for a few years now I’ve come to the conclusion that when combined these very simple measurements are a highly effective gauge of productivity.

Cycle Time

We measure cycle time as the count of working days between work starting (“in progress”) and completion (“done” or “live”) and is shown below per item over time. The chart below also shows a trend line (going down, nice) and error bars for the standard deviation:

Ideally you want to see the trendline on your cycle time chart going down, but more importantly you don’t want to see it going up. Shorter cycle times suggests we’re delivering value to the organisation quickly and do not have money unnecessarily tied up in inventory (unreleased code). It also means we’re more predictable and able to respond quickly to change.

To be truly useful (and much more difficult to game) cycle time has to measure the time it takes for things to really be done, not some “potentially shippable” nonsense. It’s also very simple to measure – you just need to track when the work starts and when it ends. We say a piece of work starts when it’s taken off the top of the prioritised queue and done when it’s been released to production (and verified). Sometimes we’ve done the analysis and requirements before hand, sometimes we haven’t (I don’t really care to be honest as we never allow more than 5-10 items in our prioritised queue so it’s not like we’re doing loads of unnecessary up front analysis or consider it a huge time drain).


We measure throughput as a count of items completed per month:

Obviously the more work we do (with the same man power) the better (but probably less bugs and more features).

Individually these measurements are useful, but can be misleading if considered in isolation – cycle time going down is great, but if you’re only delivering one piece of work a month it’s not so great. Throughput can go up or down, but could be because you’ve more or less people in your team.

It’s hard to say if productivity can really be measured by just cycle time and throughput and being witness to metrics being gamed in the past (or causing undesirable behaviour) I’m wary of trying to improve them directly. However as a couple of really simple measurements we can track over time they’re a really good guide to support or refute anecdotal evidence as to whether anything we’re doing is having an impact on our ability to deliver. A great example is the two charts above. In around Sept/Oct they show one of our team’s cycle times going down and throughput going up, which was largely a result of changing tack and spending a considerable amount of time improving the build process and removing/fixing flaky tests.

What can you try to increase your team’s throughput and reduce cycle time? What can these measurements tell us about the impact of X happening?

There are of course many other ways to judge the effectiveness of a team and I wouldn’t want to get too caught up with just these ones, but it certainly pleased me greatly to see how the team above’s measurements improved and it certainly corroborated with the mood of the team since they managed to turn things around.

I’m of the mind increasing throughput and reducing cycle time is A Good Thing™. It generally means we’re getting more done, more quickly.

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