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1.4 Master Data Model + SSOT Rules (BOM/Routing/Resources)

Master Data serves as the genetic code of the manufacturing process. If the Bill of Materials (BOM) or Routing contains an error, the MES will flawlessly execute a defect at scale. Treat Master Data not as static documentation, but as executable code that requires strict version control, validation gates, and lifecycle management.

The Digital Triad: BOM, Route, and WI

A product is defined by three interdependent datasets. These must remain synchronized to ensure the operator builds what the engineer designed.

  • Bill of Materials (BOM): The ingredients list (Components + Quantities).
  • Routing (BOL, Bill of Labour): The recipe (Operations + Sequence + Work Centers).
  • Work Instructions (WI): The visual guide (PDFs/Images linked to operations).

Synchronization Logic

  • If BOM Revision increments (Rev A → Rev B) → Flag Routing for Review. A new component often requires a new assembly step.
  • If Work Instruction does not match the active Routing Step → Block Operator Login. The risk of building to an old print is too high.

Lifecycle States & Governance

Data must mature through defined states before reaching the production floor. Implement a "State Machine" logic to prevent premature usage.

State Definitions

  1. Draft: Under construction. Visible only to Engineers. Block from Production Orders.
  2. Pending Approval: Locked for editing. Awaiting Quality/Production Manager digital signature.
  3. Released (Active): The single version of truth. Available for scheduling.
  4. Obsolete: Legacy data. Retain for warranty/genealogy, but Block from new Orders.

Transition Logic

  • If State = Released → Lock Record (Read-Only).
  • If modification is required → Create New Revision (Rev N+1). Never overwrite a Released record.

Change Control: ECO & PCN Synchronization

Engineering Change Orders (ECO) and Process Change Notifications (PCN) introduce risk. The interface between the PLM (Product Lifecycle Management) and MES must handle these transitions without disrupting active lines.

Effective Date Strategy

Avoid "Immediate" cut-ins unless safety is at risk. Use "Effective Date" or "Serial Number Cut-in" to allow WIP (Work In Progress) to flush out.

The "Flushing" Logic

When a new Revision is released:

  1. Active Orders: Continue on the Old Revision until completed (unless a Critical Safety Stop is issued).
  2. New Orders: Automatically inherit the New Revision.
  3. WIP Compatibility:
    • If Change = Form/Fit/Function → Purge WIP or Rework.
    • If Change = Documentation only → Allow WIP to finish.

Pro-Tip: Decouple the "Engineering BOM" (EBOM) from the "Manufacturing BOM" (MBOM). Engineers design functionally; Manufacturing builds structurally. The MES consumes the MBOM.

Versioning Standards

Ambiguous version numbers lead to wrong parts. Adopt a rigid syntax.

  • Pre-Production: Use Decimal or Alphanumeric (0.1, 0.2, A, B).
  • Mass Production: Use Integers (01, 02, 03).
  • Rule: A change in the BOM (Part A → Part B) always requires a revision increment of the parent assembly.

The "dirty flag" Check

Before releasing a Work Order:

  • Check: Does the checksum of the Master Data match the checksum at the time of Order Creation?
  • If mismatch → Quarantine Order. Force a planner to acknowledge the change.

Final Checklist

Category

Metric / Control

Threshold / Rule

State

Production Gate

Only "Released" state is executable

Versioning

Immutability

Released records are Read-Only

Alignment

Triad Check

BOM + Route + WI revisions match

ECO

WIP Handling

Defined strategy (Flush vs. Purge) for every ECO

Safety

Approvals

Min. 2 Signatures (Eng + Quality) to Release

Legacy

Obsolescence

"Obsolete" records blocked from new orders

Audit

Traceability

100% of field changes linked to ECO ID

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