A field service work order is the working record for one service visit. It tells the crew what to do, where to go, what the customer approved, and what changed.
The record must give the person in the field enough information to do the work and report the result.
Update the same record as the job moves through the workflow.
A job can cover the full customer lifecycle. A work order can describe one visit or task inside that lifecycle. Some systems use these terms in different ways. Define one rule for your team and use it every time.
The main purpose is to give the field worker a clear scope and to preserve a record of what happened during the visit.
It should link to the invoice or show the invoice state. The work order and invoice should use the same customer and job information.