2 posts tagged with "capacity-planning"

A team of 6 engineers, 60 working days, 8 hours each. The PM walks into the planning room with 2,880 dev-hours of capacity on the slide. Q3 roadmap fits in 2,400. Comfortable buffer. Three months later 40% of the roadmap is late and the postmortem blames "scope creep."

There was no scope creep. The capacity number was wrong on day one. Stanford economist John Pencavel's hours-and-productivity study shows output per hour starts collapsing past 49 hours per week, long before you hit 60. Microsoft Research and UC Irvine's Gloria Mark added the second blade: every interruption costs an average 23 minutes 15 seconds to fully recover focus. Stack those two findings on top of any 8-hour calendar and you get something far less than 8 productive hours of real output.

A team of 8 engineers logged 1,280 hours in March 2026. That is exactly what a 160-hour-per-FTE month should produce. The spreadsheet looked clean. Two engineers were three weeks from quitting. The hours number hid that completely; FTE utilization showed it on day five.

This is the gap between an attendance metric and an engagement-against-baseline metric. Microsoft Research's 2022 WorkLab study on the "triple peak workday" documented a third evening productivity spike pushing knowledge workers past sustainable hours, and that signal stays invisible if you only count totals. Hours don't tell you who is sprinting and who is coasting. FTE utilization does.