Estimate four components separately

When This Fires

• When creating any time estimate for a specific task
• When estimates consistently come in 30-60% low despite feeling reasonable at the time
• When planning a day and finding that "5 hours of tasks" somehow fills an 8-hour day
• Complements Three-point estimation (three-point estimation) with the component-level decomposition

Common Failure Mode

Estimating only "work time" — the time spent actively producing output. This feels like the right number because it's the time that "counts." But elapsed time includes setup, interruptions, and teardown, all of which are real time that displaces other activities. Planning based on work time alone guarantees a schedule that doesn't fit reality.

The Protocol

(1) For each task, estimate four components separately: Setup: "How long to get started? Find files, load context, prepare workspace." Core work: "How long is the actual productive work?" Interruptions: "Over this duration, how many interruptions will realistically occur? At ~23 minutes recovery each (Never apply the two-minute rule during maker time…), what's the total?" Teardown: "How long to close out, save, document, and transition?" (2) Sum all four components. This is your elapsed-time estimate. (3) Notice the gap between the core-work estimate (what your intuition gives you) and the total. This gap is the invisible overhead that causes chronic underestimation. (4) Over time, you'll develop intuition for the overhead ratios in your typical work contexts — but continue decomposing for unfamiliar tasks where overhead is harder to predict. (5) For back-to-back tasks, teardown from task A and setup for task B overlap — account for this to avoid double-counting.