---
title: "The Compound Failure Rate: Why 85% Per-Step Accuracy Means 80% Workflow Failure"
canonical: "https://current.tinyfish.ai/issue/33/practitioners-corner/article/22101/the-compound-failure-rate-why-85-per-step"
publication: "TinyFish"
publisher: "TinyFish"
language: "en-US"
guide: "https://current.tinyfish.ai/llms.txt"
issue: 33
section: "practitioners-corner"
section_name: "Practitioner's Corner"
published: 2026-06-11
updated: 2026-06-12
word_count: 76
source_links: 0
---

# The Compound Failure Rate: Why 85% Per-Step Accuracy Means 80% Workflow Failure

*June 11, 2026*

[Read on the website](<https://current.tinyfish.ai/issue/33/practitioners-corner/article/22101/the-compound-failure-rate-why-85-per-step>)

P(success) = a^m. Per-step accuracy raised to the number of sequential steps. At 85% accuracy across 10 steps, you land at 19.7% end-to-end success. Bump to 95% per step and a 10-step workflow still only clears 60%.

That's the generous version. The formula assumes independent errors. In practice, a botched early step poisons downstream context, so failures correlate. The math gives you a floor, not a ceiling. And most production workflows run longer than ten steps.

## More

- [Practitioner's Corner — Issue 33](<https://current.tinyfish.ai/issue/33/practitioners-corner/markdown>)
- [Issue 33](<https://current.tinyfish.ai/issue/33/markdown>)
- [Publication guide](<https://current.tinyfish.ai/llms.txt>)