Revision Control
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Revision Control Under GJB9001C
Revision control is the foundation upon which all configuration management activities are built. Under GJB9001C Clause 7.5.3, organizations must control documented information to ensure that technical documents and drawings are coordinated, consistent, and currently effective. Clause 7.5.3.2 explicitly requires organizations to implement "change control (such as version control)" as part of documented information management.
For PCB manufacturers, revision control means systematically managing every version of every document that defines the product — from Gerber files and fabrication drawings to assembly instructions and bills of materials. Without rigorous revision control, organizations risk producing boards from obsolete documentation, losing traceability of changes, and failing configuration audits. This guide provides a complete implementation roadmap covering document revision control, technical state revision management, configuration status accounting, and audit preparation.
Engineering Summary
- GJB9001C Clause 7.5.3 requires control of documented information including version control — a mandatory requirement for all organizations.
- Revision control applies to all technical documentation: Gerber files, fabrication drawings, assembly drawings, BOMs, test specifications, and inspection criteria.
- Technical state revision is governed by GJB 3206B — revisions to baselines must follow the four-activity framework: identification, control, accounting, and audit.
- Configuration status accounting (技术状态记实) ensures traceability of all revisions throughout the product lifecycle[reference:3].
- Key control points include version numbering schemes, document change control, obsolete document management, and revision history maintenance.
1. What Auditors Check — A Quick Overview
| Audit Focus | What External Auditors Verify | Expected Evidence |
|---|---|---|
| Document Availability | Are current versions of documents available at all points of use? | Controlled document distribution records, document registers |
| Version Control | Are documents subject to version control? Is the current revision status clearly identified? | Document revision status tables, version numbering on documents |
| Obsolete Document Control | Are obsolete documents prevented from unintended use? | Obsolete document registers, retrieval records |
| Revision History | Is a complete revision history maintained for each document? | Revision history tables, change logs |
| Document Coordination | Are technical documents and drawings coordinated and consistent? | Cross-reference checks, document relationship matrices |
| Change Traceability | Can changes be traced from request through approval to implementation? | ECR/ECO/ECN records linked to document revisions |
| Configuration Status Accounting | Is the current technical state of each configuration item recorded and reported? | Configuration status accounting records, baseline revision histories |
KEY INSIGHT:
Revision control is the most frequently audited area in configuration management. Auditors will verify that every document has a unique revision identifier, that revision history is maintained, and that obsolete versions are prevented from use.
2. Standard Requirements for Revision Control
2.1 GJB9001C Clause 7.5.3 — Control of Documented Information
GJB9001C Clause 7.5.3 establishes the fundamental requirements for controlling documented information. Clause 7.5.3.1 requires organizations to ensure that:
- Documented information is available and suitable at required times and places
- Documented information is adequately protected (against confidentiality breach, improper use, or loss)
- Technical documents and drawings are coordinated, consistent, and currently effective
- Records are complete, traceable, and can demonstrate the extent to which product and service requirements are met
- Documents and records required during product and service quality formation are archived as specified
Clause 7.5.3.2 specifies the activities for controlling documented information, including:
- Distribution, access, retrieval, and use
- Storage and preservation, including maintaining readability
- Change control (such as version control)
- Retention and disposition
- Prevention of unintended use of obsolete documented information
- Application of appropriate identification if retained for any purpose
CRITICAL REQUIREMENT:
"Technical documents and drawings shall be coordinated, consistent, and currently effective"— this requires that when one document is revised, all related documents are updated consistently. Version control is the mechanism that ensures this.
2.2 GJB 3206B — Technical State Management Revision Requirements
GJB 3206B-2022 governs technical state management for weaponry and their supporting products throughout the lifecycle. Technical state management consists of four core activities: technical state identification, technical state control, technical state accounting , and technical state verification and audit.
Revision control is embedded in all four activities:
- Technical State Identification: Determining technical state items and their required technical state documents, identifying technical state items and documents, distributing and maintaining technical state documents, and establishing technical state baselines
- Technical State Control: After technical state baselines are established, controlling change applications, deviation permits, and concession applications through论证, evaluation, coordination, approval, and implementation
- Technical State Accounting: Recording and reporting the technical state control status throughout the product lifecycle — ensuring technical state evolution is traceable
- Technical State Verification and Audit: Verifying that the product conforms to its technical state documentation
2.3 The Four "Change" Clauses — Revision Control Implications
GJB9001C-2017 contains four clauses addressing changes, each with revision control implications:
| Clause | Scope | Revision Control Implication |
|---|---|---|
| 6.3 | Change Planning — QMS changes | QMS documentation revisions must be planned and controlled |
| 8.2.4 | Changes to Product/Service Requirements | Requirement documents must be revised and re-approved; affected personnel notified |
| 8.3.6 | Design and Development Changes | All design output documents (Gerber, drawings, BOM) must be revised and version-controlled |
| 8.5.6 | Change Control — Production/Service | Process documents and work instructions must be revised and controlled |
3. Revision Control Framework — Core Concepts
3.1 Revision vs. Version — Understanding the Distinction
| Concept | Definition | PCB Example |
|---|---|---|
| Revision | A formally approved change to a document that has been reviewed, approved, and released | Gerber file V1.2 released after formal ECO approval |
| Version | An iteration of a document during development — may not yet be formally approved | Gerber file working copy before formal release (draft versions) |
In PCB manufacturing, the distinction is critical: only formally approved revisions are released to production. Working versions remain in development and are not authorized for manufacturing use.
3.2 Document Revision Status — The Revision Block
Every controlled document must include a revision block that clearly identifies:
- Revision letter/number: Current revision identifier (e.g., Rev A, Rev B, or V1.0, V1.1)
- Revision date: Date the revision was approved and released
- Change description: Brief description of what changed in this revision
- Approval signature: Authorized personnel who approved the revision
- Previous revision reference: What revision this supersedes
3.3 Document Change Control — The Revision Cycle
The document revision cycle follows a controlled process:
- Change Initiation: Change need identified — ECR created
- Change Review: Impact assessment, cross-functional review
- Change Approval: Formal approval — ECO issued
- Document Revision: Document updated to new revision
- Document Review: Revised document reviewed and approved
- Document Release: Revised document released — ECN issued
- Document Distribution: New revision distributed, old revision retrieved or marked obsolete
- Revision History Update: Change recorded in revision history
4. Revision Numbering Schemes for PCB Documentation
A consistent revision numbering scheme is essential for effective revision control. Two primary schemes are used in PCB manufacturing:
4.1 Alphabetic Revision Scheme
- Format: Rev A → Rev B → Rev C → ... → Rev Z → Rev AA → Rev AB → ...
- Use: Common for fabrication drawings, assembly drawings, and specifications
- Advantage: Simple, widely understood
- Disadvantage: Limited to 26 letters before rolling over
4.2 Numeric Revision Scheme (Semantic Versioning)
- Format: V{major}.{minor}.{patch} — e.g., V1.0.0 → V1.0.1 → V1.1.0 → V2.0.0
- Major version: Significant change affecting form, fit, function, or interchangeability (e.g., layer count change, material substitution)
- Minor version: Change that does not affect form, fit, or function (e.g., process optimization, documentation clarification)
- Patch version: Minor correction or clarification (e.g., typo correction, drawing note clarification)
- PCB Example: V1.0 → V1.1 (minor change) → V2.0 (major change)
RECOMMENDATION:
For PCB manufacturing under GJB9001C, the numeric semantic versioning scheme is preferred because it allows clear differentiation between major changes (requiring customer approval) and minor changes (internal approval).
4.3 Document Numbering with Revision
Each document should have a unique document number combined with a revision identifier:
- Format: [Document Number]-[Revision] — e.g., PCB-FAB-001-RevB or PCB-GERBER-001-V1.2
- Document number: Unique identifier for the document (unchanged across revisions)
- Revision identifier: Indicates the current revision of the document
- PCB Example:
PCB-STACKUP-001-V1.0→PCB-STACKUP-001-V1.1→PCB-STACKUP-001-V2.0
5. PCB Document Revision Control — What Gets Revised
In PCB manufacturing, the following documents must be under revision control:
| Document Type | Description | Revision Control Requirements |
|---|---|---|
| Gerber Files | PCB artwork files — all copper layers, soldermask, legend, drill, routing | Every release to production must have a unique revision. Revision must be embedded in file naming or associated documentation |
| Fabrication Drawing | Manufacturing instructions — dimensions, tolerances, materials, finish | Revision block must show current revision, date, change description, and approval |
| Assembly Drawing | Assembly instructions — component placement, reference designators | Must be coordinated with fabrication drawing revision; both must be at compatible revisions |
| Bill of Materials (BOM) | Component list — part numbers, descriptions, quantities, sources | BOM revision must be coordinated with assembly drawing revision |
| Stackup Specification | Layer structure, material types, thicknesses, impedance control | Any change to stackup requires revision and may constitute a technical state change requiring customer approval |
| Test Specifications | Inspection criteria, test methods, acceptance limits | Must be revised when inspection or test requirements change |
| Process Documents | Work instructions, process control documents, setup sheets | Must be revised when production processes change |
CRITICAL RULE:
"Technical documents and drawings shall be coordinated, consistent, and currently effective". When Gerber files are revised, the fabrication drawing, assembly drawing, and BOM must all be revised to compatible revisions. Inconsistent documentation is a major audit finding.
6. PCB Revision Control Scenarios — Practical Examples
6.1 Gerber File Revision Update
| Item | Description |
|---|---|
| Trigger | Design change requires Gerber file update — trace width adjustment |
| Revision Action | Gerber files revised from V1.0 to V1.1; fabrication drawing updated to Rev B to reflect new trace width |
| Documentation | ECR with change justification; ECO with approval; ECN with implementation instructions; updated Gerber files and fabrication drawing |
| Traceability | Revision history updated; ECN number linked to new revision; old revision archived |
6.2 BOM Revision Update
| Item | Description |
|---|---|
| Trigger | Component substitution — original capacitor discontinued |
| Revision Action | BOM revised from Rev A to Rev B; assembly drawing updated to reflect new component footprint if different |
| Documentation | ECR; ECO with engineering approval; updated BOM and assembly drawing; customer notification (if Class I change) |
| Traceability | BOM revision history shows change from capacitor A to capacitor B; ECN references new BOM revision |
6.3 Process Document Revision
| Item | Description |
|---|---|
| Trigger | Soldermask process parameter optimized for better yield |
| Revision Action | Process control document revised; work instruction updated; setup sheet revised |
| Documentation | ECR; ECO; updated process documents; training records for operators on new process |
| Traceability | Process document revision history; operator training records linked to new revision |
7. Configuration Status Accounting — Recording and Reporting Revisions
Configuration status accounting is the activity of formally recording and reporting the technical state control status throughout the product lifecycle. It ensures that the technical state evolution is fully traceable.
7.1 What Must Be Recorded
- Technical state file approval records
- Borrowing and copying records
- Change application reports
- Change approval records
- Version upgrade records
- Nonconformance review records
7.2 Revision History Table
Every controlled document should maintain a revision history table that records:
| Revision | Date | Change Description | Approved By | ECR/ECN Reference |
|---|---|---|---|---|
| V1.0 | 2026-01-15 | Initial release | J. | N/A |
| V1.1 | 2026-03-20 | Trace width adjustment — 0.127mm to 0.150mm | M. | ECR-2026-045 |
| V2.0 | 2026-06-10 | Material substitution — FR4 to high-frequency material | C. | ECR-2026-089 |
8. Key Control Points in PCB Revision Control
8.1 Document Identification
- Every document must have a unique identifier (document number)
- Every revision must be clearly identified (revision letter/number)
- Document number and revision must appear on every page
- Document identification must be machine-readable where possible (barcode, QR code)
8.2 Document Distribution and Access
- Only current revisions should be accessible at points of use
- Document distribution must be controlled (who gets what, when)
- Access must be role-based (design, production, quality, procurement)
- Electronic document management systems (EDMS) should enforce access controls
8.3 Obsolete Document Control
- Obsolete documents must be clearly identified to prevent unintended use
- Obsolete documents should be physically removed from points of use
- If retained for reference, obsolete documents must be marked "OBSOLETE" or "SUPERSEDED"
- Obsolete document registers must be maintained
- Old version stencils should be retained for 3 months for reference
8.4 Revision Locking and Design Freeze
- Establish "design freeze" milestones before production release
- Define cut-off dates for change incorporation
- Implement "version locking" — once a design is frozen, changes require formal approval
- For changes after freeze, conduct cost and schedule impact assessment
8.5 Document Coordination
- When one document is revised, all related documents must be reviewed for consistency
- Document relationships must be mapped (Gerber ↔ fabrication drawing ↔ assembly drawing ↔ BOM)
- Cross-reference checks must be performed before releasing new revisions
- Inconsistent documentation is a common audit finding
8.6 Electronic Document Management Systems (EDMS)
- Implement EDMS for automated revision control
- EDMS should enforce check-in/check-out, version tracking, and approval workflows
- EDMS should provide audit trails of all document changes
- Cloud-based solutions enable real-time collaboration and version control
9. Audit Preparation Checklist for PCB Manufacturers
| # | Check Item | Clause | Status | Notes |
|---|---|---|---|---|
| Document Control | ||||
| 1 | Document control procedure is documented and implemented | 7.5.3 | ☐ | |
| 2 | All documents have unique identification and revision status | 7.5.3 | ☐ | |
| 3 | Current revisions are available at all points of use | 7.5.3.1 | ☐ | |
| 4 | Obsolete documents are prevented from unintended use | 7.5.3.2 | ☐ | |
| Revision History | ||||
| 5 | Revision history is maintained for all documents | 7.5.3 | ☐ | |
| 6 | Revision history includes date, change description, and approval | 7.5.3 | ☐ | |
| Document Coordination | ||||
| 7 | Technical documents and drawings are coordinated and consistent | 7.5.3.1 | ☐ | |
| 8 | Gerber files, fabrication drawings, and BOMs are at compatible revisions | 7.5.3.1 | ☐ | |
| Configuration Status Accounting | ||||
| 9 | Technical state file approval records are maintained | GJB 3206B | ☐ | |
| 10 | Change approval records are maintained and traceable | GJB 3206B | ☐ | |
| 11 | Version upgrade records are maintained | GJB 3206B | ☐ | |
| Change Traceability | ||||
| 12 | ECR/ECO/ECN records are linked to document revisions | 8.3.6 | ☐ | |
| 13 | Change implementation is tracked and verified | 8.3.6 | ☐ | |
| Design Freeze and Version Locking | ||||
| 14 | Design freeze milestones are defined and documented | 8.3 | ☐ | |
| 15 | Changes after freeze require formal impact assessment | 8.3.6 | ☐ | |
10. Common Audit Findings and How to Avoid Them
| Finding | Why It Happens | How to Avoid |
|---|---|---|
| "Documents not under version control" | No systematic revision numbering scheme implemented | Implement and enforce a consistent revision numbering scheme for all documents |
| "Obsolete documents in use" | Old versions not retrieved or marked obsolete | Implement document retrieval process; mark obsolete documents clearly; use EDMS to enforce current version access |
| "Documents not coordinated" | Gerber revised but drawing not updated | Perform cross-document coordination checks before releasing new revisions |
| "No revision history" | Changes made but history not documented | Maintain revision history table in every document; link to ECR/ECN records |
| "Change not traceable to document revision" | ECR/ECO/ECN not linked to document revisions | Include document revision in ECR/ECO/ECN; reference ECR/ECN in revision history |
| "No design freeze" | Changes accepted after production start without assessment | Establish design freeze milestones; require impact assessment for post-freeze changes |
| "No configuration status accounting" | Technical state not recorded or reported | Implement configuration status accounting per GJB 3206B requirements |
11. Frequently Asked Questions
What is the difference between revision control and version control?
In GJB9001C terminology, "version control" is the broader term that encompasses revision control. In practice, "version" often refers to working iterations during development, while "revision" refers to formally approved and released document versions.
What documents must be under revision control?
All technical documents and drawings must be under revision control. For PCB manufacturing, this includes Gerber files, fabrication drawings, assembly drawings, BOMs, stackup specifications, test specifications, and process documents.
What revision numbering scheme should I use?
The numeric semantic versioning scheme (V{major}.{minor}.{patch}) is recommended for PCB manufacturing because it allows clear differentiation between major changes (requiring customer approval) and minor changes (internal approval).
How do I prevent obsolete documents from being used?
Implement a document retrieval process when new revisions are released. Use an EDMS to enforce that only current revisions are accessible. Clearly mark retained obsolete documents as "OBSOLETE" or "SUPERSEDED".
What is configuration status accounting?
Configuration status accounting is the activity of recording and reporting the technical state control status throughout the product lifecycle. It ensures that technical state evolution is traceable.
What should a revision history table include?
A revision history table should include: revision identifier, date, change description, approver, and ECR/ECN reference.
What is a design freeze?
A design freeze is a milestone before production release where the design is "locked" and changes require formal approval. Changes after freeze require cost and schedule impact assessment.
How does revision control relate to technical state management?
Revision control is the mechanism through which technical state changes are documented and tracked. Technical state management (GJB 3206B) provides the framework, while revision control provides the implementation.
Related Standards & Topics
PCB Manufacturing for Military and Aerospace Programs
UltroNiu Electronics Group provides PCB and PCBA manufacturing services under GJB9001C-compliant revision control. Contact our engineering team for program-specific documentation and revision management requirements.
Request Engineering ReviewReferences: GJB9001C-2017 Clauses 7.5.3, 7.5.3.1, 7.5.3.2, 6.3, 8.2.4, 8.3.6, 8.5.6 (Central Military Commission Equipment Development Department); GJB 3206B-2022 Technical State Management; GJB 3206A-2010 Technical State Management. Technical state management four-activity framework sourced from GJB 3206B-2022. Configuration status accounting requirements sourced from GJB 3206 series implementation guidance. PCB revision control practices based on industry best practices for military and aerospace PCB manufacturing. Courtesy of UltroNiu Engineering Knowledge Center.
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