Minimum Viable Estimate

As teams adopt more responsive software practices, one area is often left behind. We believe that the development team should deliver functionality incrementally. We know about minimum viable products. But, especially in larger companies, we hold onto the requirements until they are "done" or "right". Well-intentioned requirements groups work months getting work lined up for the developers and testers.

First, requirements, when done well, are an ever-evolving view of the product and the customer's needs. Trying to get it right in one go is like trying to ship your product in one pass. It's difficult to make anything perfect, especially requirements. The law of diminishing returns (and Little's law) kick in quickly. In other words, it's just not worth it. You'll spend far more money, and lose development runway time, by trying to perfect requirements.

I'd like to suggest we start thinking in terms of minimum viable estimates. This is not the completed estimate that's solid and can be relied upon. This is an evolving level of confidence. Understand and embrace continual elaboration and the Cone of Uncertainty. Initially we have a fuzzy idea, but it's gets better as we move forward. Here are a few steps your estimates might take.

• Gut estimate. Or maybe rough estimate. This is an off the cuff, rough order of magnitude estimate. I don't want you to do any research or assemble a team. Tell me ~right now~ how big you think this work is. Maybe in quarter year increments. This requirement looks like one quarter for a team with this expertise. That one is at least four quarters!
• Level 0 estimate. We've taken the requirement and broken it down to features. Here's how long we think it'll take, but we haven't gone too deep.
• Level 1. Now your teams have broken down the features into stories. We're finally moving towards something with solid numbers behind it.

I usually find that gut estimates are much more accurate than anyone suspects, but we're not trying to be "right". We need to be accurate enough to do rough capacity planning as early as possible and engage development earlier. Are we within an order of magnitude of our capacity? Then proceed. Otherwise let's start reining in expectations from our customers, managers and sales teams. These stakeholders rarely get everything they want, but they don't realize that they won't until the proverbial 9th hour. I'd like to get them that information earlier in the process and help them understand that they really do have to sequence (aka prioritize) the work.

And now for the weasel clause.... :)

What are these estimates? We all know they ~aren't~ estimates. True estimates can only come from the team doing the work. Just like your general contractor would never schedule your house remodeling work without talking to the subcontractors that will do the work, you shouldn't try to plan without talking to your teams. These "estimates" are just enough relative sizing to get us started. They're based on our experience with other projects, but they are only starting the first step.

What's the point?

It's that the requirements process, just like development, can benefit from a bit of transparency and diversity. Teams can begin working with you on smaller slices of work when they understand where you're heading with the work.

Often teams can start working long before you think they can… but since they have no incremental visibility into your process, they can't tell you the requirements are good enough. One feature will be solid enough for a good team to get started. Others won't be. Open the blinds and let your coworkers help with the work. They might surprise you.

And finally, the team creating requirements require feedback. Are they doing the best job possible? Probably not… no more than your developers and testers are. So let them complete a small slice of work and get the teams that consume the requirements involved. They can say "This is GREAT! I love the way this feature is described and organized. It's perfect." They might also say "I have no idea what you mean for this area… please don't write another 150 requirements this way!"

A tight feedback loop will enable your team to continually improve the process. Working without feedback rarely leads to the best product you are capable of producing and never builds a team. Involving your technical teams earlier helps the work become something you all own, instead of commandments handed down from on high.

Never forget that over 70% of our work is rework due to wrong requirements. Having another team of eyes with a different perspective will drastically improve quality.

Start with a more imprecise gut feel with rough epics and features. Involve your technical coworkers earlier. Don't be satisfied with a big bang requirements process. You'll be amazed at the effectiveness of a minimum viable requirement.