A ratio above 1.0 is mathematical proof of failure — no willpower can fix arithmetic

Why This Is a Rule

This is arithmetic, not motivation. If you have 40 hours of capacity and 50 hours of commitments, your ratio is 1.25. This means 10 hours of commitments mathematically cannot be fulfilled. No productivity hack, no time management technique, no amount of willpower can create 10 hours that don't exist. The only question is which commitments will fail — not whether some will.

The 0.85 threshold provides the variance buffer that prevents the system from tipping into overcommitment. At 0.85, you have 15% slack to absorb tasks taking longer than estimated, unplanned urgent work, and natural capacity fluctuations. At 1.0, you have zero slack — every task must complete exactly on estimate for every commitment to be met. At 1.0+, some commitments are guaranteed to fail.

This rule makes the math explicit so you can act on it rather than discovering the failure at delivery time. Seeing "ratio: 1.15" is an alarm that triggers the cut/defer/delegate response (When commitments exceed capacity, only three fixes work: cut, defer, or delegate) before any commitment actually fails.

When This Fires

• During any planning session — weekly, sprint, monthly, annual
• When accepting a new commitment that would push the ratio above 0.85
• When reviewing active commitments and calculating whether they fit available capacity
• Any moment where "I'll make it work" is the response to obvious overcommitment

Common Failure Mode

Believing willpower can override arithmetic: "I know the ratio is 1.1, but I'll work harder." You can't work 110% of available hours. The 10% overflow becomes late deliveries, dropped quality, broken promises, and eroded trust — the exact outcomes that capacity management is designed to prevent.

The Protocol

Regularly calculate your commitment-to-capacity ratio: (1) Sum all committed hours for the period. (2) Divide by measured available capacity hours (not theoretical maximum — measured; see Plan from your average capacity, not your best day — five days of measurement is enough). (3) If ratio ≤ 0.85 → healthy. Accept new work cautiously. (4) If 0.85-1.0 → warning zone. Counter-offer any new requests (Above 0.85 capacity, counter-offer new requests with a later date or explicit trade-off). (5) If > 1.0 → failure guaranteed. Immediately cut, defer, or delegate until the ratio drops below 0.85. The math is non-negotiable.