Relative Estimation - should individual skill and experience be a factor?
Hi Experts,
I have a question that I believe is not uncommon to see in real life working with teams with a mix of skills.
While doing relative estimation for a user story or backlog item, should the individual skill & experience of a team member be a factor? I understand the focus should be on team effort as the team is cross-functional but say there are two individuals on the team, one experienced in a specific skill and the other not much. If something like a planning poker technique is used, they both will share different estimates based on their experience and expertise for the same work.
For example: Team member A, estimates a story to be a 5. And, team member B, estimates it to be a 13.
Both are correct in their own space as if B is doing the work, it would be a 13 but if A is doing it would be a 5. And, trying to bring a consensus to a mid-point like 8 would result in turning both as incorrect (i.e. we reached an inaccurate estimate).
How can one overcome this problem to bring the focus of the estimation exercise on what (effort) it would need anyone in the team to complete it from how quickly an individual can complete it? This would especially be more challenging if there are different views on what it would take to complete the work due to different skill level.
What's the recommendation to deal with it or guide the team to follow?
Thank you.
Estimation is precisely that...estimation. Shouldn't a team take into account who is most likely to do the work, including any cross-training opportunities they hope to take advantage of, and keep the estimate updated as matters unfold?
As you estimate for a team and not for certain team members, how should you include skill and experience? If you did, what if the experienced is getting sick during Sprint and someone else would need to take over? Would you have both estimates available to reflect that?
Of course it makes most sense that the right person for the job does the job, but that is not always possible and that needs to be reflected. In my team if we have a situation where the expert would say 5 and other say 13 it would be discussed and in most cases the expert understands the uncertainties of the others and accept a higher estimate. But on the other hand he may also convince others that this is easier than 13 and may explain why, to convince the rest to go 8. Cooperating in the team the expert should help the other to understand and work as fast and good as possible.
But as Ian already said, it is an estimate. It is not a blood oath for which you will be hanged. Those estimates shall always reflect the team's choice and skilled and experienced developers will have a higher velocity than freshmen.
The way that I learned and have always used Planner Poker(the exercise you are describing) is that all members of the Development will discuss the item under consideration. At some point, they all agree to provide an estimate. Each member selects their own estimate and on a count of 3 they all show. If they all agree, you have an estimate. If there are differences in the numbers, there is more discussion around the estimates. The individuals with the lowest and highest are especially encouraged to share their reasons for their out lying opinions. After further discussion, you re-estimate and come to a number that the entire team can agree to accept.
This accounts for individual knowledge and forms a consensus. It also helps the team as a whole to understand how the item could be more or less complex once work begins.
As both @Ian Mitchell and @Tim Moeker stated an estimate isn't exact. Dictionary.com provides this as part of the definition of estimate
noun
an approximate judgment or calculation, as of the value, amount, time, size, or weight of something.
a judgment or opinion, as of the qualities of a person or thing.
a statement of the approximate charge for work to be done, submitted by a person or business firm ready to undertake the work.
If you get an estimate from someone to do work on your house would you expect it to be exact? When you are asked to estimate the distance between two things is there an expectation that you will be correct? No and the same should be seen with estimates derived from planning poker.