As the name says “Agile”, it does provide us with multiple metrics and agility to do things and let a team and an individual grow in career, and one such concept is “Sprint Effort Variance”.
What is Sprint Variance:
In very simple terms sprint effort variance gives the difference between the estimated time and actual spent time by any individual to complete a given task within a sprint. We are all individuals who are in the learning phase in their career and we grow with time.
Why does a team need to calculate Sprint Variance?
So, the question comes how do we measure — how as a team/individual I am growing with time. Whenever we estimate any feature saying it will take “x” number of days, that’s not the rock solid/hard estimate, it can anytime fluctuate by some percent, and the goal by using sprint variance concept is to ensure that this fluctuation reduces with time and we become better with our estimations and can provide a better picture for future sprints.
How is sprint Variance calculated:
Let’s say we have two sprints: Sprint A and Sprint B
SV — denotes Sprint Variance
X — denotes the estimated time on a task and let’s assume the number to be 20 hours
Y — denotes the time spent on the task and let’s assume the number to be 15 hours
Now the sprint Variance formula would be:
SV = X-Y
% SV = (X-Y/X) *100
Here there can be 3 scenarios:
- Positive Variance/ Number: The result will yield a positive number or positive percentage then it indicates that team member has spent less time (in Hours) in comparison of their Estimation (in Hours) within a sprint.
- Negative Variance/Number: The result will yield a negative number or negative percentage then it indicates that team member has spent more time (in Hours) in comparison of their Estimation (in Hours) within a sprint.
- Neutral: This scenario occurs when estimated and logged matches completely showing no variance at all.
Formula with example:
Sprint name: Sprint A
X — 200 hours
Y — 150 hours
SV = 200–150
SV = +50 hours
%SV = (200–150/200) *100
%SV = +25%
Sprint Name: Sprint B
X — 200 hours
Y — 300 hours
SV = 200–300
SV = -100 hours
%SV = (200–300/200) *100
%SV = -50%
Graphical representation of above calculation:
Note: We can also use excel to get this data using Pivot table.
How much variance is acceptable:
Any individual having + — 10% variance should be acceptable as we cannot be completely accurate, but for any individual/team variance going more than that can be a concern and needs analysis where the estimation is going wrong and do we need to assign more tasks or keep more bandwidth for individual/team.
For your upcoming sprints include this small step as part of your sprint closure activities that would provide you with a quantitative insight into the team’s performance and provide measurable goals for the team.
