[2020-04-24 – I’m re-doing the math on this one, since my “30 days to a month” did not take into account that we don’t work on weekends… It ends up changing the conclusion downward from 7.5 to 7 hours.]
I was looking at the updated 2013 Scrum Guide, and because of some questions that have come up at work, I looked at how much time the guide suggests as the upper limit for various Scrum meetings.
The four larger meetings look like this in the scrum guide:
(Daily Scrum: 15 minutes per day; for completeness of this list)
Planning: 8 hours per month
Review: 4 hours per month
Retrospective: 3 hours per month
Refinement: no more than 10% of available capacity
That last one was a bit of a puzzler to me. How much would that be if expressed in hours, like the other meetings?
[Previous / old calculation:
If we call “a month” 30 days, and each day 8 hours, we end up with 240 hours per month. Translating to percent of time we arrive at:
Planning: 3.33%
Review: 1.67%
Retrospective: 1.25%
Refinement: no more than 10% of available capacity
]
[New calculation:
If we call “a month” 20 days, and each day 8 hours, we end up with 160 hours per month. Translating to percent of time we arrive at:
(Daily Scrum: 15 minutes per day = 5 hours per month =~ 3.125%)
Planning: 8 hours =~ 5%
Review: 4 hours =~ 2.5%
Retrospective: 3 hours =~ 1.875%
Refinement: no more than 10% of available capacity
]
Turn that back into hours on a two week sprint (80 hours) and you get:
(Daily Scrum: 2.5 hours)
Planning: 4 hours
Review: 2 hours
Retrospective: 1.5 hour
And the kicker (after subtracting the meetings above from 80 hours, leaving 70 hours):
Refinement: no more than 7 hours, assuming “ideal capacity”
This was a HUGE surprise to me. Actually a happy surprise! I’ve heard over and over from scrum teams I work with that clarity on what to build is the biggest problem they need to work on. So the good news is that the official Scrum Guide recognizes that it’s okay to spend up to 7 hours or so (in a two week “ideal” sprint) on refinement activities, which to me include improving clarity on what to build. I only wish it hadn’t been expressed in %-of-time.