How to Share SOLIDWORKS Files with Suppliers
What is the safest way to share SOLIDWORKS files with suppliers while maintaining version control?
Aerospace Part Numbering: Hierarchical, Random, or Hybrid?
What is the best part numbering system for aerospace? Comparing hierarchical, random, and hybrid approaches.
TABLE OF CONTENTS
Part numbering is a policy problem, not a formatting trick.
Most engineering teams end up choosing between hierarchical (“intelligent”), non‑intelligent, and hybrid part-numbering systems. Intelligent numbers can be readable but brittle when parts move or get reused; non‑intelligent numbers reduce embedded assumptions but require strong metadata and search. Hybrid schemes often balance human grouping with long-term stability and error resistance.
Source note: this article draws on perspectives from an Eng‑Tips discussion among practicing engineers; direct quotes are attributed to the thread, while the frameworks, tables, and templates are editorial synthesis. See also PDM vs PLM and what PDM is.
1) Choose between hierarchical, random, and hybrid numbering
Use this table to choose a starting point. If two columns both feel “true,” you’re probably a hybrid team.
Approach | What it is | Best when… | Risks / failure modes | Practical guardrails |
Hierarchical (“intelligent”) | Part number encodes category/function/location (e.g., system → sub-system → item) | You must eyeball meaning from the identifier (field work, paper processes), and your structure is stable for years | Breaks when parts move categories; encourages “overloading” numbers when search/metadata is weak; look‑alike errors | Keep hierarchy shallow; avoid too many rules; don’t encode changing attributes (supplier, project, rev) |
Non-intelligent (sequential or random) | Identifier carries no embedded meaning; relies on description + metadata search | You have reliable search + disciplined metadata; high cost of human error; lots of similar parts | Harder for humans to “guess”; weak systems lead to tribal knowledge workarounds | Make numbers visually distinct (avoid O/0, I/1 if alphanumeric); add category via metadata, not digits |
Hybrid (“semi‑intelligent”) | Small prefix for grouping + unique/sequence segment | Most hardware orgs: need grouping and want error resistance; multiple product lines/suppliers | Prefix creep (too many categories); inconsistent rules across teams | Limit prefixes to a controlled list; keep uniqueness segment long enough; document rules and exceptions |
Forum insight (error‑proofing): several contributors argued that “smart” numbers can be costly because humans make transcription mistakes; a “fat‑fingered character should produce a wildly incorrect part.” [1]
Forum insight (findability): hierarchical systems feel attractive when people can’t reliably search descriptions/metadata and therefore push meaning into the identifier. [1]
2) Five rules for a durable numbering policy
These rules are intentionally cross‑industry; aerospace examples come later.
- Stability beats meaning. Don’t encode attributes that change (supplier, program name, location, “temporary” states).
- Uniqueness is a system guarantee, not a hope. New numbers must be created through a controlled process that prevents duplicates.
- Separate identification from revisioning. Define when a change remains a revision and when it requires a new part number—especially when interchangeability or the approved configuration changes.
- Design for human error. Avoid patterns that create look‑alikes (e.g., long similar sequences). Keep the format short enough for real workflows (labels, drawings, work instructions).
- Governance is the product. Assign an owner, define “who can mint,” document exception handling, and define “retire/obsolete” rules.
3) Numbering policy template (copy/paste)
Use this as a starting document for your team. Adjust the fields to match your tools.
Scope
- Applies to: engineered parts / assemblies / drawings / documents (choose)
- Excludes: standard hardware that already uses external standards (define)
Ownership and roles
- Policy owner:
- Part number “minting” owner(s):
- Approval workflow:
- Audit cadence:
Format definition
- Allowed characters:
- Length:
- Pattern (examples):
- Prefix list (if hybrid):
- Prohibited patterns (to prevent ambiguity):
Uniqueness and issuance
- When a new number is required:
- How duplicates are prevented:
- How placeholder / temporary numbers are handled:
Revision separation
- Where revision lives:
- What triggers a revision vs a new part:
- How released vs in‑work states are represented:
COTS and supplier parts
- When you keep supplier PN vs assign internal PN:
- What metadata must be captured (manufacturer, spec, approved substitutes, compliance notes):
- Obsolescence handling:
Retired numbers and reuse policy
- Can numbers be reused? (recommended: no)
- How “obsolete” is represented:
- Record retention expectations:
Required metadata (minimum set)
- Description naming rules:
- Category/system:
- Material/spec:
- Make/buy:
- Supplier/manufacturer (if applicable):
- Compliance/traceability fields (regulated contexts):
Tip: Copy/paste this template into your internal policy doc, then tailor the fields to your tools and approval workflow.
4) Aerospace / regulated / multi‑supplier considerations (vertical example)
Aerospace raises the cost of getting this wrong because of long lifecycles, multi‑supplier supply chains, and traceability expectations. Forum contributors emphasized that numbering decisions affect configuration control, maintenance support, and the ability to identify parts decades later. [1]
Relevant standards (what they support — and what they don’t)
- ATA iSpec 2200: supports consistent aircraft system classification and technical information structuring; it does not, by itself, define a company’s internal part-number policy. [2]
- ASME Y14.100 / ASME Y14.41: support engineering drawing / digital product definition documentation practices; they can influence how identification appears on drawings, but they are not a universal “best practice” for how every organization must construct part numbers. [3] [4]
- FAA guidance on replacement parts identification/traceability: supports the claim that traceability and part identification matter in regulated aviation contexts. [5]
- EASA continuing airworthiness rules (record-keeping): supports the claim that organizations must retain and manage records to demonstrate continuing airworthiness, which increases the value of stable identifiers and disciplined metadata. [6]
Practical implications
- Traceability expectations tend to push teams toward stronger governance and richer metadata (not necessarily more “intelligent” digits).
- Configuration control (STCs, mods, multiple approvals) increases the need for clean revision separation and clear “released vs in‑work” states. [1]
- COTS management becomes harder over time; forum anecdotes highlighted how losing purchasing context can cause real operational risk. [1]
5) How a PDM system supports (but doesn’t replace) numbering policy
A PDM/PLM system can make a numbering policy easier to follow by (depending on its capabilities and configuration):
- enforcing required metadata on creation,
- preventing duplicate identifiers where the system supports controlled issuance,
- improving search so teams don’t overload part numbers with meaning,
- keeping change history and approvals auditable.
But a tool cannot decide:
- what constitutes a “new part” vs “revision,”
- who has authority to mint identifiers,
- how exceptions are handled,
- how COTS is normalized across suppliers.
Treat the numbering policy as governance first; then configure your tools to support it.
For planning implications, compare PDM deployment timelines and the cloud vs on‑premise PDM TCO tradeoffs.
CAD ROOMS Scope: What It Does and Does Not Do
CAD ROOMS manages CAD files, revisions, releases, and engineering change workflows. It does not currently generate or validate part numbers, detect duplicate parts, or provide complete BOM and structured part‑metadata management.
Teams can use CAD ROOMS to maintain controlled file history and release records alongside an external part-numbering policy. The policy must still define identifier issuance, revision‑versus‑new‑part decisions, COTS handling, and required metadata.
CAD ROOMS also supports file-level governance controls such as Unique Filenames (workspace-wide filename uniqueness across projects). This helps prevent duplicate filenames, but it is not part-number governance. See: Create a workspace — File settings (Unique Filenames).
Conclusion
Choose the simplest numbering policy that preserves uniqueness, survives part reuse, and can be governed consistently. Use metadata and controlled records for information that may change; do not force changing attributes into the identifier.
FAQ
Should aerospace part numbers contain meaningful information?
Sometimes—but only if the meaning is stable and the organization can enforce the rules. Meaningful numbers can improve recognition in the field, but they can also become rigid when parts are reused or reclassified. Many teams succeed with hybrid numbering: limited, controlled context plus a uniqueness segment and strong metadata/search.
What is the difference between non-intelligent, sequential, and random part numbers?
“Non‑intelligent” describes whether the identifier carries meaning; “sequential” and “random” describe how the identifier is generated. A non‑intelligent numbering system can therefore use either sequential or random issuance. The key is that identification relies on description + metadata, not digits. In either case, design for transcription errors and avoid look‑alike patterns.
How should COTS parts be numbered?
Either keep the manufacturer part number or assign an internal identifier—both can work. What matters is governance: capture manufacturer, supplier, spec, approved substitutions, and approval/qualification context as metadata so traceability and re-buying remain possible years later. Forum anecdotes highlight how losing purchasing context becomes an operational risk. [1]
Does ATA iSpec 2200 define company part numbers?
Not by itself. ATA iSpec 2200 is commonly used as a system classification and documentation framework in aerospace. Teams may align internal categorization or metadata to ATA chapters, but company part-number formats are still a company policy choice.
What PDM capabilities support a non-intelligent numbering system?
Look for reliable search, required metadata enforcement, identifier issuance controls, duplicate detection (where supported), audit trails, and controlled release/change workflows. These capabilities reduce pressure to encode meaning into the identifier.
References
[1] Eng‑Tips Forum (2025). Part numbering conventions – what’s the best practice in aerospace?
[2] Airlines for America (A4A) Publications. iSpec 2200: Information Standards for Aviation Maintenance (product page)
[3] ASME. Y14.100 — Engineering Drawing Practices (official standard listing)
[4] ASME. Y14.41 — Digital Product Definition Data Practices (official standard listing)
[5] FAA Advisory Circular AC 20-62E. Eligibility, Quality, & Identification of Aeronautical Replacement Parts
About the author
Christina Rebel
CEO of CAD ROOMS | Co-founder of Wikifactory
I'm Christina Rebel, CEO of CAD ROOMS. For over a decade, I've worked at the intersection of cloud engineering collaboration, digital manufacturing, and distributed product development.
Throughout my career, I've worked closely with engineers, designers, and manufacturing teams to improve CAD data management, version control, supplier collaboration, and browser-based design review. My focus is on making modern engineering workflows more accessible, secure, and efficient, particularly for SMEs and startups. I also write about engineering collaboration, with contributed articles published by Design News and DEVELOP3D.
Follow the author: LinkedIn
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