Evidence and download retention

Obsidian Metra stores official records (the audit trail you must keep) separately from generated downloads (files created for export).

When a generated file expires, only that file is removed from download. The official records remain.

This page explains product behavior. It is not legal advice and does not set your organisation's retention policy.

Source records vs generated downloads

A CSV or ZIP is a snapshot. Expiry of that snapshot does not mean the source records expired.

Calibration certificate supersession

The first upload sets the current certificate version for an event. Replacing a certificate creates a new version and requires a reason.

The old version is marked superseded, not deleted or overwritten. Its metadata remains, including:

• filename and media type;
• file size and SHA-256 checksum;
• who uploaded it and when;
• version and status;
• reason for replacement;
• related audit entries.

When a calibration event is submitted, the selected certificate version is frozen. A later replacement does not silently change what was already submitted or approved.

Controlled evidence revisions

Controlled documents are versioned PDFs with fixed revisions:

• each uploaded revision stores metadata and checksum;
• one revision is marked approved;
• approving a newer revision supersedes the earlier approved one;
• old approved revisions stay in history for audit traceability.

When a dossier is submitted, Metra freezes selected revision IDs, sizes, and checksums so later document updates do not change that frozen dossier.

Archiving a controlled document changes its state; it does not delete revision history.

Historical asset evidence packs

A historical pack groups one equipment item and one date range with one or more source documents.

Key points:

• Verification is performed for the full pack.
• Calibration staff uploads still require independent approval.
• Quality managers/administrators/owners confirm the correctness declaration.
• After submission, files in that pack are not edited individually.
• Corrections create a new replacement pack; previous packs stay retained.
• Voiding requires a reason.
• Only verified current packs are used in newly generated formal evidence.

Compliance export retention

Compliance exports are CSV or ZIP files made from a frozen snapshot.

• A completed export is available for 7 days by default.
• Download requires organisation-scoped authentication.
• After expiry, cleanup removes the generated file and marks the job as expired.
• Job metadata, filters, counts, timestamps, checksums, and audit history remain.
• Source records (equipment, certificates, events, investigations, audits) are unaffected.
• Re-running the request creates a new job from a new snapshot; it does not restore expired files.

Dossier artifact retention

A dossier is frozen when approved, then a ZIP is generated from that frozen snapshot.

• A generated dossier archive is available for 90 days.
• After expiry, the dossier shows expired and the archive is removed from active download.
• Dossier metadata, frozen scope, source IDs, warnings, generated-file metadata, checksums, source records, and audit history remain.
• A new dossier revision is required after expiry; the same revision is not regenerated.

Metadata and checksum retention

Checksums are used for file integrity. Metra stores SHA-256 checksums for:

• source files;
• generated artifacts;
• filenames, media types, file size;
• upload/requester identity;
• timestamps, versions, and lifecycle state.

manifest.json records each included file’s path, media type, size, and checksum. Use it to verify a downloaded archive before storing or sharing it.

Retention responsibilities

Metra does not set legal or contractual retention periods for you.

Before a temporary download expires:

1. Decide if the artifact must be kept elsewhere.
2. Download it from the app while still available.
3. Verify checksums or manifest when your process requires it.
4. Store the copy in an approved controlled location.
5. Apply your organisation’s own access/disposal policy.

Expiry of a downloaded copy does not automatically mean source evidence can be deleted.

Related guides

• Upload or replace a calibration certificate
• Import historical equipment evidence
• Manage the controlled evidence library
• Create a compliance export
• Generate an equipment evidence pack
• Generate and download a dossier
• Search the audit trail
• ISO 17025 dossiers