In Estimating Effort – An Explicitly Implicit Approach I stated that time cannot be one of the attributes the team uses to describe what they mean by “effort.” The importance of this warrants the need for a deeper dive into the rationale behind this rule and how excluding time can lead to better predictability for team performance.
The primary objective for coaching teams to think about effort independent of time constraints is so that they can improve their skills for thinking about the actual work involved. Certainly they will spend time completing the work. But the simple passage of time won't get the work done. Someone has to actually DO something. That something is the effort.
For example, maybe someone on the team says the product backlog item requires a lot of documentation. It isn't complex and there aren't any dependencies, it's just going to take a lot of time - 7 days, maybe. So they want to give that PBI an effort value of 5 or 8 (or 5 or 8 story points, if that's what you're using) because it's going to take a lot of time.
Remember, the purpose of these criteria is to generate a conversation around what the actual effort is. The criteria are just a set of guideposts that help the team hold a meaningful conversation about the effort. So when someone on a team insists that they estimate using time, I ask them "What are you doing as the time you've estimated is passing? Are you just sitting there, watching the seconds tick away?" Of course they aren't just sitting there. I'm asking the questions to elicit a comment about the actual work they are doing. Maybe they answer with something a little less vague, like "typing words." That's good. "What's the difference between typing those words in a word processor and typing code in Vim?"
Continuing down this line of inquiry usually leads to the realization that typing documentation has many similar traits to coding. It can be complex. It may have dependencies. It may require research for accuracy and it certainly will need a lot of debugging (professional writers call this "editing.") Coders typically don't like writing documentation. To them it's just about the tedium of banging something out that's not as fun as code. Sussing out the effort like this will lead to better acceptance criteria and definition of done associated with the PBI.
The downside of time estimates is that they hide all manner of sins and rabbit holes. The planning fallacy, precision bias, availability heuristic, and survivorship bias are just a few of the mental obstacles guaranteed to reduce the accuracy of time estimates. Or you may have to deal with a team member who wants to estimate using time because they know full well it offers the opportunity to hide slow work. (Gamers gotta game.) When teams have run the gauntlet of effort criteria, they are more likely to end up with a better picture of how much work they are being asked to do when time is excluded from the conversation. Effort criteria force the team to be more explicit about the activities they are engaged with as the clock ticks.
The investment in identifying time-independent effort criteria yields further benefits in the retrospective. Was the team unable to complete a PBI in the sprint? Was all the work finished two days early? Have a look at the effort criteria and ask which of them were a factor in making the PBIs a bigger or smaller effort than initially estimated. This is how teams learn and improve their skill at estimating. The better they are at estimating the more predictable their productivity.
OK, so let's say you have a team doing a great job of determining the effort needed to complete a PBI and they do so without including time. No doubt, management will be unimpressed. They want time estimates. Good news! We can give them time estimates...in two week increments.
With the team focused on figuring out time independent effort values for every PBI in the backlog and an ongoing experience of how much effort they can reliably complete in two week increments, product owners can provide a reasonable forecast for when the release or project will be complete. The team focuses on accurate time independent effort estimates. The scrum master and product owner worry about the performance metrics and time projections.
It's surprising how hard of a sell this can be for teams. They are hard wired to think in terms of time because that's what traditional project management has hounded them for since before coding was a thing. I tell teams, "With Agile and scrum, you no longer have to worry about time. That's the product owner's job. But you do have to develop very good skills at estimating effort." It's common for them to have a hard time adjusting to the new paradigm.