Chain of Custody

What is it?

The chain of custody is a complete traceability record per test object: it records who had custody of the test object when, where it physically was, and why that changed (received, handed over, relocated, returned, disposed of). For accredited labs (ISO/IEC 17025), such traceability is often mandatory; for everyone else, it answers the everyday question "where is test object X right now?".

Additionally, every test object in the chain gets a scannable short code (e.g., TO-7K3P9M). You can print this code as a barcode/QR label, stick it on the test object, and scan it at the station to jump straight to the correct detail page.

How to use it

• Recording an event: On a test object's detail page, in the Chain of Custody section, click Record event. Choose the type (e.g., "Handed over"), enter holder (who) and location (where) — both required — and optionally a note. The first recorded event automatically assigns the scannable code.
• Picking a holder: The "Holder (who)" field suggests matching members of your organization as you type; click a suggestion to use it. Free text is also allowed (e.g. "External lab" or "Courier DHL") when custody lies outside the app. It defaults to your own name — handy for the common case of taking custody yourself.
• Chain sequencing: The first event on a test object is always "Received" — it must be taken into custody somewhere before it can be handed over, relocated, returned, or disposed of. Once the most recent event is "Returned" or "Disposed", the chain is considered closed: the Record event button disappears and a hint explains why. To continue anyway (e.g. after an accidental disposal), delete that closing event (see below) and record a new one.
• Photo for an event: When recording, you can optionally attach a photo (e.g. the test object's condition at handover, a signature). Up to three photos per event. Photos appear as thumbnails right in the chain — click one to see it enlarged.
• Current state: At the top of the section you always see the current holder and location — derived from the most recent event. Below that, the full chain runs chronologically.
• Code / label: The short code is shown in the section. Click it to see it enlarged as a QR code — handy for scanning it straight off the screen with your phone, or click Print to print it as a label (the print view hides the rest of the page). If a test object doesn't have a code yet, assign one via Assign code.
• Deleting an event: A delete icon appears next to an event when you recorded it — e.g., to fix a typo right after recording. Admins and owners can additionally delete events recorded by other members, e.g. to clean up a colleague's mistake. Every other role can only delete their own events. The deletion itself remains traceable in the audit log, even though the event disappears from the chain.
• Scanning: Test objects → Scan test object. Scan the label (a barcode scanner behaves like a keyboard) or type the code — you land directly on the detail page. On a phone or tablet without a connected scanner, tap Scan with camera to open your device's camera and point it at the QR label — the code is read automatically and you're taken straight to the detail page. This button only appears when the browser supports camera access.

Common issues

• "The current holder is wrong." The current state is always the most recent event (by event time). If an event was recorded with the wrong timestamp, record a correcting follow-up event or delete the faulty event if you recorded it yourself (see above) — the chain is otherwise deliberately append-only and is never overwritten.
• "I can't record a new event." Either you lack permission (see below), or the chain is closed: the most recent entry is "Returned" or "Disposed". If that was a mistake, delete that last entry and record a new one.
• "Only 'Received' can be picked for the first event." That's by design: the chain always starts with taking custody of the test object.
• "I can't delete an event." You can only delete events you recorded yourself, not ones recorded by other members. Admins and owners can also delete other members' events.
• "Scanning doesn't find the test object." The code doesn't belong to any test object in this organization, or it was typed incorrectly. The code consists of TO- plus six characters, excluding the easily confused 0/1/I/L/O/U. Check the label or search for the test object via the list.
• "A test object has no code." A code is created automatically on the first custody event. You can also generate one in advance via Assign code.
• "The camera scanner doesn't start / asks for permission." Your browser needs permission to use the camera; allow it when prompted, or check your browser's site settings if you dismissed the prompt earlier. If your device has no camera, or the browser doesn't support camera access, the Scan with camera button won't appear at all — use the manual input field instead.
• "Who can record events?" Any member can read; recording requires the Member role or above. Viewers see the chain but can't change it.
• "Can a colleague see someone else's code?" No. Codes and events are bound to the organization; tenant isolation applies here too at the database level.