Can anyone help to understand " Refinement usually consumes no more than 10% of the capacity of the Development Team."
Here is my understanding :
Estimated Capacity of a team = Committed dev team members x( Effective Hours x No.of Sprint Days)
Hypothetically team members is = 4 (Fully committed) Effective hours/per person = 6 Hrs No. Of Sprint Days = 20 days(1 month sprint)
So the Capacity = 4*(6*20) = 480 man hours. 10% of 480 is = 48 hours which can be spent for the product backlog refinement.
Is it Time-Boxed? do we need to convert this as a time-boxed of 2 days or 48 hrs for a sprint of one month? in this case the time box varies based on the effective hours invested based on person's focusing factor.
No, backlog refinement is not a timeboxed event in Scrum. It's a responsibility of the Scrum Team, and one to be fulfilled within each Sprint timebox. The 10% figure is merely a guide to help shape an activity that should happen on an ongoing basis.