Process Instance

A process instance is one specific run of a process definition. The definition is the diagram — the abstract description of what happens. The instance is a single execution of that definition for a single case: "invoice 2026-0472", "candidate Marie Dupont", "support ticket #8812". Every activity inside that instance has exactly one state (pending, in progress, completed); the definition has none.

A process instance is the unit that BPMN engines track. When you see a dashboard showing "237 running instances of the Invoice Approval process", each of those 237 is a distinct instance with its own tokens, data, and history. The diagram is shared across all of them; the instance state is not.

A process instance can have many tokens simultaneously — one for each active parallel branch, plus one in each running sub-process, plus any in multi-instance iterations. Tokens are the execution markers inside the instance; the instance is the container. When all tokens are consumed by end events (or a terminate end event fires), the instance completes.

• One instance — one execution, one customer, one case.
• Many tokens per instance — one for each concurrently active path.
• Many instances per definition — the same diagram, running simultaneously for many cases.

LucidFlow computes "cost per instance" and "cost per month" separately, and the distinction matters. Cost per instance is the weighted expected cost of running the process once — what you would pay for a single invoice, ticket, or onboarding. Cost per month is that number multiplied by the monthly execution frequency — what the business actually spends. When you see the cost dashboard say "$42 per instance, $12,600 per month at 300 instances", the first number is the design cost and the second is the burn rate.