Interruptions and recovery time fragment work; modeling them with three parameters (interruption rate, recovery minutes, focus threshold) shows how they collapse productivity and how small changes can dramatically increase deep work.
Focus at work is being hijacked by a steady stream of interruptions. The author models a workday as a Poisson process with three knobs: λ (interruptions per hour), Δ (minutes to recover), and θ (minimum uninterrupted block needed for real work). By visualizing a bad day and a good day, the post shows how a high λ and long Δ shred a day into tiny gray recovery periods, leaving only a single deep work block.
The post walks through concrete examples: a day with λ=2/hr, Δ=20 m, θ=60 m yields just one 81-minute focus block and 19 interruptions costing 242 minutes. In contrast, lowering λ or Δ produces multiple deep blocks, up to 137 minutes, and dramatically higher capacity. The capacity formula C(θ)=Σ⌊di/θ⌋ quantifies how many usable work units a day contains, making the impact of fragmentation crystal clear.
Real-world data backs the model: studies report 7.5 email/IM alerts per hour and 10-16 minutes of resumption time, while Microsoft's 2025 work trend index finds heavy collaborators interrupted every two minutes (λ≈30). The author uses these numbers to simulate 100-day runs, showing distribution of focus block lengths under different λ and Δ settings, reinforcing that even modest reductions in interruption rate can free substantial deep-work time.
Technical leaders can use this framework to audit their own teams' interruption rates, enforce meeting-free windows, and design tooling that reduces Δ. By turning vague complaints about "lack of focus" into measurable parameters, the article gives a practical path to reclaiming productive time.
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