In high-tech device manufacturing, evidencing quality is part of the build. Whether you build scientific instruments or components for healthcare, customers and auditors expect a clean trail from materials to final release.
A Batch Manufacturing Record (BMR) is that trail: the clear, unit-ready story of what you built, which revision you followed, which gauges or test rigs you used, and how each result was signed off. For teams evaluating MRP for medical device manufacturers or MRP for scientific equipment, a solid BMR process transforms audits from a scramble into a routine check, making investigations faster and fairer for small UK workshops.
Done well, a BMR is short, searchable and complete. It links lots and serials to the right drawing and routing, captures inspection and test results at the point of work, and ties in any ECNs or NCRs without extra paperwork.
The rest of this guide shows what to include, how to keep admin light for small MTO/ETO teams, and how an electronic batch record plugs straight into planning, production and aftersales inside your MRP.
BMR, MBR and DHR — how they differ
Three terms often get mixed up:
- MBR (Master Batch Record): the approved “recipe” — drawings, BOM, routing and acceptance criteria. You copy from this when you start a batch.
- BMR: the executed record for one batch. It shows what actually happened on the shop floor, against the current MBR revision.
- DHR (Device History Record): device-makers often need proof at unit level as well as batch level. The DHR is usually your BMR plus per-serial test/inspection pages and final release for each finished unit.
For small MTO/ETO teams, the distinction matters. The MBR keeps everyone building to the same standard. The BMR proves you followed it. The DHR lets you trace any one device from label to test result in seconds.
Why small device manufacturers need BMRs that fit reality
A lot of online advice assumes big plants and stable processes. Many UK device manufacturers are different: small teams, mixed custom and semi-custom work, frequent changeovers, and one or two constrained assets — often a single functional test rig. Quality gates such as first-article inspection aren’t box-ticking; they’re how you protect your reputation. On top of that, you may need to capture calibration IDs, software or firmware versions, and occasional engineering changes mid-build.
That’s why a practical BMR for small teams should be clear, lean and complete. Clear so anyone can follow it. Lean so you’re not buried in admin. Complete so an auditor — or your future self — can trust it.
What a device BMR should include (in plain English)
You don’t need a monster pack. You need the essentials, captured cleanly:
- Header and identifiers: job/batch number, product code/description, MBR/drawing revision, customer PO and due date.
- BOM snapshot at release: what you intended to build, with the revision you actually used.
- Materials evidence: the lots you issued; serialised critical parts where relevant.
- Operations carried out: which steps you ran (assembly, inspection, test), where, and by whom, with start/finish times.
- Inspection and test results: including first-article results and the acceptance criteria you applied.
- Equipment and calibration: the gauges/metres/rigs used, plus their calibration due dates.
- NCR and rework: any non-conformances, what you did about them, and the re-test evidence.
- Software/firmware (if used): version/build ID and release approval.
- Labelling and serials: the finished-goods serial list and label checks.
- Change control: ECNs applied during the run and the pages they affected.
- Sign-offs: operator and QA approvals, plus the final release.
Keep each section brief and legible. The goal is traceability without paperwork fatigue.
Batch plus serial — how to structure it without drowning in admin
Most device makers work with batches of units, but still need serial-level proof. The tidy way to do this is:
- Keep one BMR per batch for the shared story (materials, ops, approvals).
- Add a unit page for each finished serial that holds the key test/inspection results, any label checks and the final sign-off.
- Cross-reference the unit pages inside the BMR (a simple serial list with page numbers is enough).
- This keeps the main record compact while giving you unit-level confidence when a customer asks about “Device 1007”.
Paper BMR or Electronic Batch Record (EBR)?
Paper can work for very small volumes, but it’s easy to miss a field, hard to version-control, and slow to search. An Electronic Batch Record reduces those risks:
- Required fields and dropdowns prevent blanks and typos.
- Version control ties the batch to the right drawings and routing.
- E-signatures and audit trails speed up CAPA/NCR work and external audits.
- Search means a calibration ID or ECN number is seconds away.
A good rule of thumb: if your NCRs are rising, audits are becoming more frequent, or ECNs land mid-build more than occasionally, it’s time to move to EBR.
A simple example: ten units on the bench
Picture a 10-unit bench build. Stores issue the parts; you record the lots. Assembly runs in small batches, with a first-article signed off before the rest. In-process checks are logged as you go.
Units reach the functional test rig, where each serial gets its result recorded. Two units need rework; you raise an NCR, record the fix, retest and pass. Midway through, an ECN #014 arrives — you attach it to the pack and note which steps it affects.
At the end you attach the final serial list, capture the calibration IDs used on test equipment, and QA releases the batch.
That’s all a BMR is: a faithful, tidy account. Nothing more complicated than that.
Five mistakes that invalidate BMRs (and how to avoid them)
- Building to the wrong revision. Print or pin the right MBR/drawing revision to the pack; block release if it’s missing.
- Missing operator/time stamps. Make key fields required — no sign-off if blank.
- Unlinked ECNs. Add the ECN number on the BMR cover and attach the revised pages.
- No calibration traceability. Record equipment IDs and due dates on each relevant check/test page.
- No serial cross-references. Keep a serial list and unit pages; don’t rely on memory when a customer asks six months later
FAQs
What is a batch manufacturing record?
It’s the documented history of producing a specific batch: materials used (with lots/serials), the operations you ran, results and sign-offs. It proves you built to the approved spec.
What’s the difference between BMR, MBR and DHR?
The MBR is the master recipe. The BMR is what you actually did for one batch. The DHR adds unit-level proof for device makers.
Do I need a BMR for one-offs or prototypes?
Yes, but keep it light. You still need traceability and the ability to learn from issues, even for a single unit.
How do I handle mixed batch + serial traceability?
One BMR per batch, then short unit pages for each serial with the test/inspection results and final sign-off. Cross-reference them in the BMR.
What belongs in a device BMR that wouldn’t appear in a food/process record?
Typically: serial lists, functional test results, calibration IDs, software/firmware versions, and tighter change-control links.
What is an EBR and when should I adopt it?
An Electronic Batch Record is a digital BMR with validation, e-signatures and audit trails. Switch when errors, audits or changes make paper too risky or slow.
Bringing this to life in Flowlens
Set up your MBR templates once (BOM, routing, acceptance criteria), then spin up BMRs that inherit the right revision. Capture lots and serials at goods-in and issue. Record inspection and test results and reference the calibration of any equipment used. Link any NCRs to the batch and keep the serial pages together. Because everything is electronic, audits and customer questions stop being a trawl through filing cabinets.
Ready to see how it works in the real world?
Book a time for a quick, no obligation workflow demo with Flowlens.
