A workflow can complete every visible node and still produce the wrong business outcome.
One reason is structural: a multi-step system inherits upstream misses. If every step is only usually correct, the end-to-end success rate is not the average of those rates. Under a simple independent-step assumption, it is their product.
I built a free browser-only reliability calculator to make that multiplication visible. Paste one to thirty per-step percentages; the calculation runs locally, uploads nothing, and asks for no email.
Seven 85% steps do not make an 85% workflow
Suppose a workflow has seven steps and each one succeeds 85% of the time.
