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

Master Data serves asis the geneticexecutable code of theyour manufacturing process.factory. If the Bill of Materials (BOM) or Routing contains an error, the MES will flawlessly executeautomate the production of a defect at scale.defect. Treat Master Data not as static documentation, but as executablea coderigid configuration set that requires strict version control, validation gates, and lifecyclecryptographic management.integrity.

TheCanonical DigitalMaster Triad:Data BOM, Route, and WIEntities

A productproduction isprocess definedrelies byon threefour interdependentdistinct datasets.data Theseentities. Each entity must remainhave synchronizeda unique immutable identifier (Primary Key) to ensureprevent the operator builds what the engineer designed.ambiguity.

• 1. Bill of Materials (BOM):

  • Definition: The ingredientshierarchical list (Componentsof components and raw materials.
  • Primary Key: PartNumber + Quantities)Revision (e.g., PCBA-1001-Rev02).
  • Constraint: A BOM must never be modified in place. Any change requires a new Revision ID.

  2. Routing (BOL, Bill of Labour):Labor)

  • Definition: The recipesequential (Operationslist of operations, capable work centers, and standard times.
  • Primary Key: RouteID + SequenceRevision.
  • Constraint: Every Operation Step must map to a valid Resource Type.

  3. Resources (Work Centers)

  • Definition: Physical assets (Machines, Lines, Benches) or Logical groups (Test Stations).
  • Primary Key: AssetID (Physical) or ResourceGroupID (Logical).
  • Constraint: Resources must have an Active / Maintenance / Decommissioned state flag.

  4. Recipes / Programs

  • Definition: Machine-specific files (PnP placement files, Reflow profiles, ICT test scripts).
  • Primary Key: ProgramName + Checksum (MD5/SHA256).
  • Constraint: The MES must verify the machine loaded the exact program specified in the Routing.

  Pro-Tip: Decouple the Engineering BOM (EBOM) from the Manufacturing BOM (MBOM). Engineering designs by function; Manufacturing builds by assembly step. The MES consumes the MBOM.

  Synchronization Logic

  The integrity of the system depends on the alignment of these entities. Use the following logic to enforce the "Digital Triad" (BOM + Route + Work Centers)Instruction).

• Work Instructions (WI): The visual guide (PDFs/Images linked to operations).

Synchronization Logic

• If BOM Revision increments (Rev A → Rev B) → Then Flag Routing for Review.Mandatory AReview. new(New componentparts often requireschange a newthe assembly step.process).
• If Work Instruction doesRevision not≠ match the activeActive Routing Step Revision → Then Block Operator Login.Login. The risk of(Prevent building to anobsolete oldprints).
• If printRecipe isChecksum tooat high.Machine ≠ Checksum in MES Master Data → Then Trigger Electronic Interlock (Stop Line).

Lifecycle StatesState & GovernanceMachine

Data must mature through defined states before reaching the production floor.states. Implement a "strict State Machine" logicMachine to prevent premature usage.or unauthorized usage of data on the shop floor.

State Definitions

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

Transition LogicRules

• If State = Released → Then Lock Record (Read-Only).
• If modificationModification is required → Then Create New Revision (Rev N+1).
• If. NeverCritical overwriteQuality Issue detected → Then Force State to "Hold" or "Obsolete" immediately.

Drift Controls & Reconciliation

Over time, the ERP (Financial view) and MES (Floor view) will drift apart without active policing. Implement these automated controls to detect and block drift.

1. Blocking Conditions

• Checksum Mismatch: Before releasing a ReleasedWork record.Order, calculate the hash of the BOM+Route. If Hash(Order) ≠ Hash(MasterData) → Then Quarantine Order.
• Ghost Resources: If Routing specifies Resource_A but Resource_A is flagged "Decommissioned" → Then Block Scheduling.

2. Reconciliation Reports

Run a nightly comparison job between ERP and MES databases:

• Orphaned Parts: Items existing in MES BOMs but deleted/inactive in ERP.
• Unit of Measure (UoM) Conflicts: ERP uses "Each", MES uses "Meters". Action: Flag for manual correction.

Change Control: ECO & PCNFlushing SynchronizationStrategy

Engineering Change Orders (ECO) and Process Change Notifications (PCN) introduce risk. TheYou interfacemust betweendefine exactly how a change enters the PLMproduction (Productstream Lifecycleto Management)avoid andmixing MES must handle these transitions without disrupting active lines.revisions.

Effective Date Strategy

Logic

Avoid

• Immediate: "Immediate"Stop cut-insline. unlessPurge safetyall isWIP. at risk. Use "Effective Date" or "Serial Number Cut-in" to allow WIP (Work In Progress) to flush out.

  The "Flushing" Logic

  When aSetup new Revision is released:

  1. Active Orders: Continue on the Old Revision until completedrevision. (unlessUse aonly for Safety/Critical Safety Stop is issued)Quality).
  2. NewRolling Orders:(Flush): AutomaticallyAllow inheritcurrent theWIP to finish on Old Revision. Start Newnew Orders on New Revision.

WIP Compatibility:Compatibility Logic

• If Change =affects Form/Fit/Function → Then Purge WIP or Rework.Rework.
• If Change =is Documentation onlyOnly → Then Allow WIP to finish.complete.

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

Versioning StandardsSyntax Standard

AmbiguousAmbiguity versionkills numbers lead to wrong parts.traceability. Adopt a rigid syntax.syntax to distinguish prototype data from mass production data.

• Pre-Production: Use Decimal or Alphanumeric (0.1, 0.2, A, B).
• Mass Production: Use Integers (01, 02, 03).
• Rule: A change in thea BOMchild component (Part A → Part B) always requiresforces 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 executableexecutable.
VersioningIntegrity	Immutability	Released records are Read-Only (No "Edit", only "Revise").
Alignment	Triad Check	BOM + Route + WI revisions matchmust match.
Drift	Nightly Reconciliation	0 Orphaned Parts; 0 UoM conflicts.
Recipes	Machine Control	Recipe Checksum in MES = Recipe Checksum on Tool.
ECO	WIP Handling	Defined "Flush" vs "Purge" strategy (Flush vs. Purge) for every ECOchange.
SafetyAccess	Approvals	Min. 2 Signatures (Eng + Quality) to Release
Legacy	Obsolescence	"Obsolete" recordsMaster blocked from new orders
Audit	Traceability	100% of field changes linked to ECO IDData.