Master Manufacturing Record (MMR) – Device-Class Master Definition for Repeatable, Auditable Production

This topic is part of the SG Systems Global regulatory & operations glossary.

Updated October 2025 • Records & Definition • MES, LIMS, ELN, Lot Traceability

The Master Manufacturing Record (MMR) is the authoritative, version-controlled definition of how a finished medical device—or a regulated product managed under device-style governance—is to be manufactured and verified every single time. In the device world the MMR sits alongside the Device Master Record (DMR) and is referenced by the Device History Record (DHR); in mixed portfolios it plays a role analogous to the Master Batch Record (MBR) used under drug 21 CFR 211, but its governance and content align primarily to device 21 CFR 820. The MMR codifies materials, components, subassemblies, work instructions, tooling and equipment requirements, inspection and test methods, acceptance criteria, labeling and UDI rules, environmental and cleanliness conditions, packaging configurations, and release steps with signature meaning—then binds those requirements into an execution stack so they cannot be ignored. When executed within a modern MES and integrated to LIMS and ELN where applicable, the MMR is no longer a passive document: it becomes an operational contract with hard gate stops that prevent the wrong part, wrong torque, wrong label, or wrong sterilization lot from ever slipping through under pressure.

“An MMR is not a manual—it’s a safety interlock cast in prose, compiled into software, and proven by an audit trail.”

1) What the MMR Must Contain—Beyond a Procedure Binder

A defensible MMR goes far deeper than a stack of work instructions. It captures the bill of materials (BOM) with approved manufacturer and supplier parts, alternates, and critical attributes that affect form, fit, function, and sterilization compatibility; it enumerates device families, revisions, and configuration rules so serialization and labeling logic are deterministic; it specifies process parameters—torque, angle, speed, temperature profiles, cure times, vacuum levels, cleanliness class, and ESD protections—alongside the specific equipment classes and fixtures allowed, with calibration, preventive maintenance, and IQ/OQ/PQ status gates. It defines in-process and final inspection plans that include sampling schemes, AQL levels, measurement methods, gage requirements (R&R), and environmental conditioning for metrology; it sets acceptance criteria with units, rounding, and decision rules harmonized with the LIMS or inspection module. For packaging and labeling, the MMR prescribes materials, seal parameters, GS1 GTIN / HRI construction, and device identifiers with print-and-verify logic, and it defines when and how EPCIS events are posted. Finally, it codifies release steps—what must be signed by whom with meaning—and which prerequisites (component and subassembly genealogy, inspection pass, sterilization lot release, CoA/sterility assurance) are hard requirements before a DHR can close.

2) MMR vs. MBR—and Why the Distinction Matters

While both MMR and MBR are “master” definitions, they live in different regulatory dialects and emphasize different risks. The MBR focuses on batch-based process control for drugs and biologics under 21 CFR 211, where blending, potency, and content uniformity dominate; the MMR is rooted in discrete assembly, subassembly control, and device verification under 21 CFR 820. Practically, that means the MMR must be explicit about component-level identity and alternates, torque and angle programs, fixture and tooling IDs, poka-yoke measures, and end-of-line functional tests. In mixed environments—combination products, med-tech consumables, or diagnostics with reagents—SOPs often muddle MMR and MBR language; don’t. Keep the masters pure to their risk model, then reconcile at execution with a unified MES route where drug-like steps (e.g., reagent prep) obey batch rules and device-like steps (e.g., assembly) obey MMR rules, each with their own gates and evidence.

3) From MMR to the Shop Floor—Compilation to eMMR/eDHR

The master by itself doesn’t stop errors; compilation does. An approved MMR should compile automatically into an electronic MMR (eMMR) or eDHR route inside MES, resolving device revision, options, and work centers into the exact steps technicians will see. Each step should pull the correct work instruction revision, tooling setup, and parameter set; bind to stations that can read torque tools, vision systems, leak testers, balances for gravimetric fill, or PLCs; and impose asset status checks and line-clearance photo evidence where needed. Identity is verified at every handoff via barcode validation against component reservations with FEFO for shelf-life-limited items. Measurements stream in as raw, attributable signals: torque/angle curves, force-displacement profiles, leak test decay curves, mass/tare/gross values, and vision inspection results with images. The MES must refuse to advance if raw data violates limits—even if a rounded display appears “close”—and it must capture reason-for-change, second-person verification, or approved rework when policy allows. A route that begs for “supervisor override” is an uncontrolled process with decorative software.

4) Inspection Planning and Metrology—What the MMR Has to Nail

Device quality collapses when inspection plans are vague. The MMR needs to explicitly reference each inspection characteristic, its measurement method by document number and revision, the instrument class with calibration interval, and any measurement system analysis (MSA) requirements (R&R targets) so readings are credible. For variable data, define units, precision, rounding, and decision rules; for attribute checks, define reference standards and acceptance images. Tie sampling to lot size using defined AQL levels and escalation rules. If a characteristic is monitored with SPC control limits, codify alert/action thresholds and what actions are required at each threshold, then have the MES enforce stop-to-correct. Push raw data to LIMS or an inspection module so the DHR isn’t a pile of unsearchable PDFs; future CPV demands trending that can only come from structured data with provenance intact.

5) Materials, Alternates, and Obsolescence—Control at the Part Level

Most device escapes start with a part. The MMR should define allowed alternates, critical attributes, and supplier approvals at the line-item level with links to drawings, specifications, and component release status. For electronics, specify firmware versions and configuration EEPROM programming; for adhesives, specify lot-based pot life and environmental constraints; for sterile barriers, define seal parameters and sampling for integrity tests. Obsolescence rules belong in the master: last-time-buy handling, equivalency assessment steps, and the requirement for Change Control with validation evidence before an alternate becomes active. Tie warehouse logic—directed picking, dynamic lot allocation, FEFO—to the MMR’s shelf-life and storage conditions so MES cannot accept an expired or out-of-temperature component even if it physically fits. If the part makes the product possible, the MMR must make the part undeniable.

6) Tooling, Programs, and Fixtures—Fit-for-Use Is Not Optional

For programmable tools—torque drivers, cobots, PLC stations, vision systems—the MMR must define the approved program IDs, checksum or hash values where feasible, and the method by which MES verifies the loaded program matches the master before allowing production. For fixtures and gauges, record serials and maintenance intervals; require pre-use checks documented with photos or automated readings. Interlock use on calibration status and cleaning validation where product cross-contact is a risk. If the tool settings aren’t verified at step start, you are trusting memory and habit in a system that is supposed to remove both from the risk surface.

7) Labeling, UDI, and Serialization—Make Counterfeiting Hard and Mistakes Harder

Labels are how your product tells the world what it is—and how investigators will prove what went wrong. The MMR must fix label templates under Document Control with versioned variable fields that the MES populates from the route (device model, revision, serial, lot, manufacturing date, sterilization date/lot, country/regional marks), and it must force print-and-verify at the printer and again at point-of-use. UDI construction with GS1 GTIN and (01)/(10)/(17)/(21) elements should be deterministic; where multiple labels are applied (device, tray, shipper), the MMR must define the parent-child links and post EPCIS events for external partners. For reprints or relabels, require scan-back of the original identifier and a reason code. If you can produce a label outside MES without creating a traceable, attributable record, you’ve created a bypass around your entire quality system.

8) Environmental Controls, Hygiene, and Line Clearance—Proof Before Motion

Device assembly often depends on cleanliness and environment more than people admit. The MMR must specify environmental ranges (temperature, humidity, differential pressure), cleanliness/ESD gowning requirements, and the EM sampling plan tied to alert/action limits. For start-up, changeover, and post-interruption, require line clearance with photographic evidence and dual verification steps; interlock the route until evidence is captured and approved. Where medical adhesives, solvents, or sterilized components are used, codify dwell times, open-time maxima, and container re-closure rules with scan-based timing in MES so violations block automatically. Hygiene isn’t about posters on the wall; it’s about proof in the DHR that the prerequisites existed when you said they did.

9) Rework, Scrap, and Nonconformances—Branches, Not Backdoors

Real plants rework; weak systems pretend they don’t. The MMR must define allowed rework branches with explicit criteria, additional inspections, and new acceptance limits; forbid ad-hoc technician improvisation; and require NC/deviation creation when rework falls outside defined branches. Every removal or replacement needs genealogy: scan-out the serial/lot being removed, scan-in the replacement, capture reason codes, and force second-person verification on safety-critical actions. Scrap must trigger label destruction workflows and component reconciliation to prevent “ghost stock” driving wrong picks later. If rework and scrap don’t modify genealogy, you’ve told the MES a fairytale your customer will unravel after launch.

10) Governance—Document Control, Change Control, and Validation Under 820/11/Annex 11

The MMR lives or dies by governance. Draft under engineering control, review with production and quality, and approve under Document Control with clear effectivity. Changes must pass through formal Change Control with risk assessment, impact to CSV, and training plans. For electronic records and signatures, align to 21 CFR Part 11 and Annex 11 with unique users, role-based access, time sync, secure audit trails, and validated backup/restore. Under 820, ensure the MMR aligns with DMR structure and that DHR closure is contingent on all MMR-mandated evidence. If your governance lets a technician print an old instruction because “the new one isn’t trained yet,” your risk isn’t theoretical—it’s daily.

11) Metrics—Proof the MMR Is Doing Its Job

Measure Right-First-Time assemblies, block events by category (identity mismatch, out-of-status tool, inspection fail, environment out-of-range), program mismatch detections on torque/vision/PLC stations, label verification failures, rework branch usage vs. ad-hoc NCs, DHR closure lead time, and release lead time. Trend by device family, station, shift, and supplier. Feed findings into APR/PQR and CPV. The quality of your MMR is visible in how rarely people can even attempt to do the wrong thing—and in how quickly records close when they simply follow the route.

12) Common Failure Modes—and How to Design Them Out

Program drift and “nearly right” settings: Torque/angle programs or vision recipes shift locally. Fix: include program IDs and checksums in the MMR; have MES verify at step start and block on mismatch. Right part, wrong revision: Warehouse issues the correct model with an obsolete rev; assembly proceeds. Fix: bind picks to reservations carrying rev and alternates; enforce scan-before-use and block on rev mismatch. Inspection without gating: Data is collected, route advances regardless. Fix: mark inspection steps as hard-gate with LIMS or inspection module disposition; store raw signals and decision rules. Label/UDI errors: Off-system labels or uncontrolled reprints. Fix: print from controlled templates in MES, require scan-back and reason codes for any reprint, and verify at point-of-use. Shadow spreadsheets: Offline torque logs, leak data, or fixture checks erode provenance. Fix: stream device data into MES; disable uncontrolled exports and require attachments for exceptions. Environment ignored: Out-of-range builds pass unnoticed. Fix: bind EM data to route start and require proof before motion; block on out-of-range with documented disposition.

13) How This Fits with V5

V5 by SG Systems Global treats the MMR as executable truth. In V5 MES, the MMR compiles into station-aware routes that verify tool programs, enforce asset status, require line-clearance photos, and gate on component identity before any measurement is accepted. Inspection steps generate work in the quality stack; results flow from the lab or inspection cell via the V5 QMS – LIMS Integration and automatically toggle Hold/Release states—no acceptable result, no advance. Labels print from versioned templates, are verified at print and application, and—when required—publish EPCIS events for trading partners. Every action creates an attributable, immutable audit trail in line with Part 11 and Annex 11, and the eDHR closes only when the MMR’s evidence checklist is green. Analytics expose program mismatch catches, block events by cause, and DHR closure lead time, feeding supplier scorecards and design feedback. In short: V5 makes the MMR non-negotiable and provable.

FAQ

Q1. How is an MMR different from a DMR?
The MMR defines how to manufacture and verify; the DMR is the complete device “recipe” that includes design outputs (drawings, specs, software) plus the manufacturing records. The MMR is a core component of the DMR and drives the eDHR during execution.

Q2. We build combination products. Do we need both MMR and MBR?
Yes—use an MMR for discrete device steps (assembly, inspection, packaging) and an MBR for drug-like operations (reagent prep, fill, cure) under 211. Compile both into a single MES route with separate hard gates appropriate to each regime.

Q3. Can technicians deviate if a torque is slightly out but still “feels” right?
No. The route should block acceptance, require rework per the MMR branch, or escalate via controlled deviation/NC with engineering/quality approval and full attribution.

Q4. What electronic controls are mandatory?
Unique users, role-based access, e-signatures with meaning, synchronized time, secure computer-generated audit trails, validated backup/restore—aligned to Part 11 and Annex 11.

Q5. What metrics prove our MMR is effective?
Right-First-Time assemblies, block events caught early, zero “manual overrides,” label verification pass rate, rework confined to defined branches, short DHR closure time, and stable CP/CPK on critical characteristics—pulled from system data, not spreadsheets.

Related Reading
• Core Definitions: Master Batch Record (MBR) | MES – Manufacturing Execution System | ELN | LIMS
• Execution & Records: eMMR | DHR | Audit Trail (GxP)
• Controls & Integrity: Barcode Validation | Control Limits (SPC) | Poka-Yoke
• Traceability & Release: Lot Traceability | CoA | Finished Goods Release
• Compliance Foundations: 21 CFR Part 820 | 21 CFR Part 11 | Annex 11 | GAMP 5