Workflow conversations often mix up three different layers: how we sketch a process, which tools validate the sketch, and what actually runs in production. This post separates those layers by comparing flowcharts, statecharts (FSMs), and BPMN, so you can choose the right tool for the job.

What is a diagram#

A diagram is a visual model of behavior, structure, or flow. It helps people share understanding faster than plain text by showing relationships, order, and boundaries in one view.

What is a Durable Workflow?#

A durable workflow is a long‑running, stateful business process that automatically remembers where it left off, survives crashes or restarts, and can resume or retry instead of starting over.

Unlike a simple script that runs once and dies, a durable workflow:

• Persists its state (current step, variables, context) in a database or durable store
• Handles timeouts, retries, and failures without losing progress
• Supports human‑in‑the‑loop steps, approvals, and external events (e.g., a user clicking “confirm”)

In effect, durable workflows bring human‑like resilience to automation: they pause, recover, and continue, just like a person who remembers what they’ve already done.