Subcontracting Purchase

Purchase integration with subcontracting

The MRP Subcontracting Purchase module tightly integrates Purchase and MRP Subcontracting. This module allows creating purchase orders for subcontracted products, automatically calculating lead time, managing component resupply to subcontractors, tracking subcontracting and material costs, linking PO, MO and pickings, and reporting BOM structure for subcontracting.

Purchase Order
Subcontracting
Resupply
Lead Time
Cost Tracking

Key benefits

Key points

  • Automation: Automatically creates component resupply

  • Transparency: Full tracking from PO to MO

  • Accuracy: Calculates lead time combining vendor and manufacturing

  • Accounting: Correctly calculates subcontracting costs


Installation and configuration

This module is automatically installed when you have MRP Subcontracting and Purchase MRP.

Steps

  • 1. Go to Purchase → Vendors to configure subcontractors.

  • 2. Check Is a Subcontractor and select Subcontracting Location.

  • 3. Set Delivery Lead Time.

  • 4. Configure product with Routes: Resupply Subcontractor on Order.

  • 5. Create BOM with BoM Type: Subcontracting.


Integration workflow

The workflow starts with creating a Purchase Order, then the system automatically creates a Manufacturing Order and Resupply Pickings for components. Materials are sent to the subcontractor, the subcontractor manufactures, and finally finished products are received with cost recording.


Order types

Purchase order types

TypeDescriptionExample
Standard POPurchase finished productsBuy from supplier
Subcontracting POPurchase subcontracting serviceHire a subcontractor for manufacturing
Resupply POPurchase materials for subcontractorSend components

Create subcontracting purchase order

You can create a subcontracting PO manually or let the system generate one from reordering rules. After confirmation, the purchase order becomes the starting point for the whole resupply, manufacturing, and receipt flow.

Steps

  • 1. Go to Purchase → Purchase Orders.

  • 2. Click Create.

  • 3. Select Vendor (subcontractor).

  • 4. Add Product (subcontracted product), Quantity, and Unit Price.

  • 5. Click Save and then Confirm Order.

  • 6. Review the automatically created Manufacturing Order, Resupply Pickings, and Receipt.


Manage component resupply

The system automatically creates outgoing pickings to send materials to the subcontractor. From the PO, you can open the Resupply smart button to inspect pickings, check availability, and choose between full or partial shipment.

Steps

  • 1. Open the Purchase Order and click the Resupply smart button.

  • 2. Check the Operations tab for components, quantities, and source location.

  • 3. Click Check Availability so the system reserves stock.

  • 4. If components are missing, create a replenishment PO or transfer stock from another location.

  • 5. Click Validate to ship the full quantity or create a backorder for a partial shipment.

  • 6. Track subcontractor stock in Inventory → Locations through the subcontracting location.


Lead time calculation

Subcontracting lead time is calculated from the vendor Delivery Lead Time, the BOM Manufacturing Lead Time, Days to Prepare MO, and purchasing processing time. This makes Expected Arrival and Production Start Date more realistic for outsourced production.

Key points

  • The general formula is max(Vendor Lead Time, Manufacturing Lead Time + Days to Prepare MO) + Days to Purchase.

  • Example: if Vendor Lead Time is 10 days, Manufacturing Lead Time is 7 days, Days to Prepare MO is 2 days, and Days to Purchase is 1 day, the total lead time is 11 days.

  • You can inspect the lead-time breakdown from the Replenish flow to review Receipt Date, Vendor Lead Time, Manufacturing Lead Time, and Production Start Date.

FieldsTrường dữ liệuDescription
Delivery Lead TimeThời gian giao hàngVendor delivery time from vendor info.
Manufacturing Lead TimeThời gian sản xuấtSubcontractor manufacturing time from the BOM.
Days to Prepare MOThời gian chuẩn bịPreparation time before manufacturing from the BOM.

Cost tracking and accounting

Subcontracting cost usually combines the service cost on the PO, the component cost already sent to the subcontractor, and any additional overhead. When the receipt is validated, the system records stock valuation, journal entries, and the movement of value from the subcontracting location into finished goods.

Key points

  • For Standard Cost products, the subcontracting service cost is often the difference between standard cost and component cost.

  • Open the Purchase Order to review subcontracting cost, components cost, and total cost in the related information.

  • Check valuation entries when the total cost or inventory value does not match expectations.


Smart buttons and document links

Smart buttons on the PO and related pickings let you move through the full document chain without manual searching.

Common navigation links

LocationButtonPurpose
Purchase OrderResupplyOpen pickings that send components to the subcontractor
Purchase OrderManufacturingOpen manufacturing orders created from the PO
Purchase OrderReceiptOpen the finished-goods receipt
Stock PickingSource PO / ManufacturingTrace back to the source PO or related MO

BoM structure reporting

The BoM Structure & Cost report helps analyze component trees, lead-time breakdown, resupply routes, and cost structure for subcontracted products.

Key points

  • Review Component Cost, Subcontracting Cost, and Total Cost in one place.

  • Check Manufacturing Delay, Days to Purchase, and Total Lead Time to validate your lead-time setup.

  • Use the report when you need to explain why a subcontracted product has a higher cost or longer replenishment time.


Common issues

Key points

  • If resupply picking is not created, verify BoM Type = Subcontracting, component routes, and the subcontracting location on the vendor.

  • If lead time looks wrong, update Delivery Lead Time on the vendor and Manufacturing Lead Time plus Days to Prepare MO on the BOM, then recreate the PO.

  • If costs look incorrect, check the product Cost Method, valuation entries, and whether all components were shipped and recorded properly.

  • If smart buttons are missing, confirm that the PO actually generated resupply, manufacturing, or receipt records and that the user has access to them.


Practical tips

Key points

  • Create templates for recurring subcontracting POs to reduce repetitive data entry.

  • Set reordering rules and lead-time buffers for products with volatile vendor performance or production duration.

  • Track KPIs such as on-time delivery rate, lead-time accuracy, and cost variance by subcontractor.

  • Combine monthly reconciliation with vendor performance reviews to detect stock or cost discrepancies earlier.