Once a project plan identifies high-level tasks, the engineering team can T-shirt-size them: assign each task a relative effort category—Large, Medium, Small, or Extra Small. This gives the team a first view of the workload before estimating smaller tasks. section 10.1.3
Set a scale that fits your team
One possible scale is Large = 12 weeks, Medium = 8 weeks, Small = 4 weeks, and Extra Small = 2 weeks. Adjust those values to your team’s needs; they are not universal rules. section 10.1.3
After sizing, estimate granular tasks—using story points if the team follows an agile method. Compare the resulting effort with developer capacity or budget. If they do not align, discuss reducing scope, changing the timeline, or adding resources. section 10.1.3
