Budgeting for software projects in “scrum team years.”

It’s often said that if you want to know how long it will take to complete an Agile software project, then you should get started on building it. The theory is that once you have your backlog built out, your stories sized, and you know your velocity thanks to a few months of work, you can get a rough idea of how long it’ll take to complete the whole thing. (Henrik Kniberg explains this in his “Agile Product Ownership in a Nutshell” video.) And that might be fine in some scenarios, but in organizational contexts, it’s often impossible to get started without funding, and it’s impossible to get funding without having a defensible estimate of how long a project will take…which is difficult to do without getting started. What’s to be done?

There are a lot of bad ways to estimate software projects costs, and they fall into two camps: qualitative estimates (“I did something like this once and it took about 10,000 hours, so that’s how long this will take”) and quantitative estimates (“this is similar to these three other projects, which have an average of 600,000 lines of code, and historical data shows that line of code takes 1 minute to write, so this will require 10,000 hours”).

In government, in practice, neither of these are used. Instead, an agency publishes an request for information, vendors provide ballpark figures that are rarely rooted in any defensible math, the agency then makes a request for funding based on those responses (e.g. by tossing out the high and low numbers and averaging the remainders), funding is awarded, the agency publishes a request for proposals, and the bids come back for prices real close to that awarded funding. At any step of the way, if anybody asks why the cost is, say, $20 million…well, that’s not actually explainable. There is no internal logic that underlies this price tag. The result has been 20 years of spiraling of costs for custom software in government, as prices have gradually gone up because they are tethered to nothing but the amount of money that vendors say it’ll cost, and they have every incentive to provide a big number.

There is a better way: “scrum team years.”

Federal labor data shows us that the blended hourly rate for each member of a scrum team averages about $125, or about $235,000 (at 1,880 hours per year). A scrum team, therefore, will run you $1–2 million, depending whether it’s closer to four members or nine.

When procuring a major custom software project, you can interrogate the reasonableness of the price by breaking down the price into scrum team years. Is the bid for $20 million? Then you should be getting between 10–20 scrum team years, perhaps as 5 scrum teams working for 4 years, perhaps as 5 scrum teams working for 2 years, or any number of other mathematically plausible variants. Experienced software developers can compare the complexity of a project to the number of scrum team years and have a sense as to whether the price makes sense.

This works at an agency level, this works at a procurement level, this works at a budgeting level. It allows people who lack deep expertise in software development (which is to say nearly everybody involved in the entire budgeting and procurement process) to have some basic unit of value to compare and debate. (Does this project really require 500 people working for 5 years? What could we get from 10 people working for 6 months? Wait, we’re only getting 10 scrum-team years but we’re paying $50 million? And so on.)

It’s even possible to interrogate the price tag more deeply, if it’s arrived at thoughtfully. In the same way that a scrum team will generally estimate story sizes (“pointing stories”) before pulling them into a sprint, it’s also possible to use experience—some of that qualitative analysis—to make estimates at much larger scales. This will suffer from the same problems that plague standard estimation methods, but for the purpose of establishing a rough order of magnitude, when used by people with significant experience executing comparable projects, it’s an internally-coherent, externally-validatable approach. Reasonable minds can disagree as to whether creating (say) a basic account-creation system might require more or less than one month of work by a scrum team, but breaking down a project into a dozen or so such units and recording the estimated effort level for each unit allows those minds to disagree meaningfully and productively.

Scrum-team years are a good estimation tool for aligning program teams, budgeting, procurement, and oversight, giving everybody a common currency of understanding.

Published by Waldo Jaquith

Waldo Jaquith (JAKE-with) is an open government technologist who lives near Char­lottes­­ville, VA, USA. more »