Structural Topology & Custody Modeling

Subcontracting requires a precise model of where assets physically reside, who legally owns them, and how formulations translate inputs into finished outputs. This topology prevents the mistaken treatment of third-party-held stock as sold, lost, or consumed before production is complete.

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1. Stock Custody Hierarchy

Finished output and component stock move through a strict custody chain. Each node represents a distinct accounting and operational status.

Main Warehouse (Company-Owned)
└── Subcontractor Virtual Location (Company-Owned, Third-Party Custody)
    ├── In-Process / Awaiting Receipt
    └── Quarantine / Inspection (Returned FG Pending Release)
        └── Sellable Finished Stock (Company-Owned)

Custody Level	Ownership	Physical Custodian	Accounting Treatment
Main Warehouse	Principal	Principal	Raw/component inventory asset at standard valuation location.
Subcontractor Virtual Location	Principal	Subcontractor	On-book external asset; value remains on principal’s balance sheet.
Quarantine / Inspection	Principal	Principal or Subcontractor	Finished asset held pending quality release; no revenue or cost recognition change.
Sellable Finished Stock	Principal	Principal	Finished inventory asset ready for sale or internal consumption.

Custody Rules

• The Subcontractor Virtual Location is a logical extension of the principal’s warehouse network. It is not a customer site, not a supplier site, and not a consignment sale location.
• Multiple subcontractors may each have one or more virtual locations, segmented by site, production line, or campaign.
• Components in a subcontractor virtual location remain unavailable for direct sale or internal consumption until they are transformed and received back as finished goods—or explicitly returned to the principal’s warehouse.

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2. Legal Ownership vs. Physical Location

A foundational principle of the Subcontracting domain is the separation of legal ownership from physical possession.

Dimension	Legal Ownership	Physical Location
Definition	The party holding title to the asset and bearing its value on the balance sheet.	The geographical or logical place where the asset is physically stored or processed.
Subcontracting Treatment	The principal retains full ownership of all components and finished goods until they are sold to a customer or internally consumed.	Components are physically at the subcontractor’s premises; finished goods may be returned to the principal or held at the subcontractor under a virtual location.
Risk Implication	Loss, damage, or shrinkage before formal receipt remains the principal’s risk and is reported as scrap or variance.	The subcontractor is contractually responsible for safe custody, but the asset still belongs to the principal.
Insurance & Compliance	Insurance coverage and inventory audits must explicitly include subcontractor-held stock.	Physical counts and cycle counts must reconcile subcontractor virtual locations independently.

Ownership Invariants

• Components dispatched to a subcontractor are never recognized as an expense, sale, or disposal.
• Finished goods received from a subcontractor are not purchased from the subcontractor; they are capitalized from the principal’s own components plus the tolling service fee.
• The subcontractor is compensated for services rendered, not for materials supplied (unless the subcontractor also supplies some materials under a separate procurement arrangement).

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3. BOM Structure: Multi-Tier Consumption

The Bill of Materials defines the component-to-finished transformation. In subcontracting, the BOM explicitly separates material inputs from processing services.

BOM Composition

Finished Good SKU
├── Material Components
│   ├── Empty Bottle (1.020 units per FG unit)
│   ├── Cap (1.000 unit per FG unit)
│   ├── Label (1.000 unit per FG unit)
│   ├── Active Ingredient (0.500 kg per FG unit)
│   └── Packaging Carton (0.100 unit per FG unit)
└── Service Components
    ├── Tolling / Processing Fee (per FG unit)
    └── Setup Charge (per production run)

Material vs. Service Lines

Line Type	Source of Value	Capitalization Behavior	Owned By
Material Component	Existing inventory value of dispatched components	Transferred from component cost layers to finished good cost layers upon backflushing.	Inventory / WMS
Tolling Fee	Service PO line rate × accepted finished quantity	Added to finished good inventory value as a service cost.	Procurement / FMS
Setup Charge	Fixed amount per campaign or batch	Allocated across the finished quantity of the campaign, or treated as a campaign-level cost based on accounting policy.	Procurement / FMS

Conversion / Yield Modeling

The BOM expresses both theoretical input and expected output to support planning and variance analysis.

Concept	Definition	Example
Theoretical Input	The exact component quantity required for one finished unit at 100% efficiency.	1 bottle + 1 cap + 1 label = 1 finished unit.
Planned Input (with yield)	Theoretical input inflated by expected scrap or loss.	1.02 bottles per finished unit to cover breakage.
Actual Input	The quantity backflushed based on actual finished receipt.	1,020 bottles consumed for 1,000 finished units.
Yield Variance	Difference between planned and actual consumption after tolerances.	Actual consumption of 1,030 bottles against a planned 1,020 triggers a variance investigation.

Multi-Tier Considerations

• Some subcontracting operations involve nested subcontracting: a semi-finished intermediate is produced by one subcontractor and then dispatched to a second subcontractor for final packaging. Each tier must maintain its own virtual location, BOM, and SCO.
• The domain tracks component lineage across tiers using lot references and polymorphic document aliases, ensuring traceability without direct database coupling.