In this guide 6 sections
A work order tells the floor what to build, how many and by when, while a device history record proves what was built, with which components and tests. One drives production. The other is evidence. Good systems link them by lot number.
Two documents, two jobs
The work order is an instruction that says make five hundred units of a given part number, using this bill of materials, on this route, by Friday. Planners create it and the floor reads it.
The device history record, or DHR, is a result: it shows the components consumed, the steps completed, the test readings and the release decision.
Plan forward with the first. Prove backward with the second. Never mix the two.
What sits inside a device history record
The record is built for one lot or serial number, and each line answers a question that an inspector or a customer might ask years later. Dates and names matter as much as numbers.
For a sterile catheter that means resin lot, extrusion line, tip forming temperature, leak test pressure, pouch seal check and the sterilisation load number. For a hospital bed the same record holds frame weld inspection, castor torque, motor serial and the final electrical safety test, each signed by its operator.
Most of this content does not exist when the work order is released, because it appears only as operators scan components and enter readings during production. A DHR cannot be a copy of the work order with ticks added, and a blank template has to be filled step by step as production moves along.
- Quantity made and quantity released
- Component lots actually consumed
- Process steps with operator and date
- Test and inspection readings against limits
- Labels used and label reconciliation
- Release signature and date
Where the two get confused
A common mistake is to treat the closed work order as the history, though it rarely shows the component lot, the gauge or the approver of a deviation. It shows quantity and dates.
The second mistake runs the other way, when a planner reads an old DHR to schedule a new run and copies stale routing steps. A DHR records what happened once.
Keep the two views apart. Link them by lot number.
- Work order: planned quantity and due date
- Work order: current bill of materials and route
- DHR: actual consumption and readings
- DHR: deviations and who approved them
How a deviation moves between them
Suppose a supplier ships a substitute screw for a bed rail: the planner changes the bill of materials on the work order and the floor builds the lot. The DHR must now show the substitute, the approval and the test that followed, or the record will contradict the physical lot sitting in the warehouse.
If your tool lets the planner edit the work order after release without a trace, the DHR no longer matches what the work order said at the time. Lock the work order at release. Log every change after it.
A change log is dull. It still saves an argument during an audit. Keep it.
Setting them up in software
Create the work order first and generate an empty DHR template tied to its lot number, so the template fills itself as operators scan components and enter readings. Release stays blocked until required fields are complete.
For a first step, take one product and write down every field its DHR needs, then compare that list with today’s paper traveller. Those gaps show what your system must capture, so settle the list before you speak to any vendor, and bring it to the first demo.
Work order and DHR field map
This sheet has two columns, work order and device history record, with a row for each field, such as quantity, component lot, route step, gauge and release signature. A third column names who fills it.
Open a blank worksheet to printQuestions owners ask
Can one document serve as both?
Not safely. The work order changes before and during production, while the history record must stay fixed once released, and joining them hides every edit made after release.
Who owns each document?
Planning owns the work order. Quality owns the history record. Production operators fill in both documents at different points, and the quality head signs the release that closes the history record for that lot.
Do we need a DHR for every unit?
That depends on the device and your rules, but many makers keep one record per lot, with serial detail for implants or powered devices. Check with your quality lead.
What happens if the DHR is incomplete?
The lot should not be released. Missing readings or signatures are resolved first, and any gap that remains is recorded as a deviation with a named approver and a written reason.