Managing Subcontractors: Tracking Costs and Quality on Outsourced Work
- The Surface Treatment Subcontractor Who Cost £22,000 in Rejects
- The True Cost of Subcontracting: What Most Factories Miss
- Setting Up Subcontractor POs and Material Tracking
- Incoming Quality Control for Subcontracted Work
- Subcontractor Agreements: The Clauses That Protect You
- Before and After: A UK Automotive Components Factory
- Managing Multiple Subcontractors: Keeping Visibility Across the Network
- Treat Subcontractors as Managed Suppliers
Outsourcing work to subcontractors introduces cost and quality risks that SMB factory managers frequently underestimate. Without systematic subcontractor cost tracking and quality monitoring, the savings from outsourcing are often lower than projected and the quality failures are higher than expected.
- The Surface Treatment Subcontractor Who Cost £22,000 in Rejects
- The True Cost of Subcontracting: What Most Factories Miss
- Setting Up Subcontractor POs and Material Tracking
- Incoming Quality Control for Subcontracted Work
- Subcontractor Agreements: The Clauses That Protect You
The Surface Treatment Subcontractor Who Cost £22,000 in Rejects#
A South Wales precision engineering firm outsourced its hard chrome plating to a local subcontractor — work that required specialist equipment the company did not want to invest in. The arrangement worked well for three years. In year four, the plating subcontractor changed its process chemical supplier and, without notifying its customers, the plating adhesion characteristics changed subtly. Parts that passed the subcontractor's standard inspection failed the engineering firm's incoming quality check at a rate of approximately 30%. The subcontractor disputed the failure analysis; the engineering firm had already committed to delivery dates. Emergency alternative sourcing took 8 days. By the time the situation was resolved, the engineering firm had scrapped approximately 1,200 plated parts (value £8,400), incurred emergency re-plating from a more expensive alternative at £6,200, and paid £7,400 in customer expediting costs and air freight. The total £22,000 cost came from the absence of systematic incoming quality control and a process change notification requirement in their subcontractor agreement.
The True Cost of Subcontracting: What Most Factories Miss#
The direct cost of subcontracting — the price charged by the subcontractor — is visible on every invoice. The indirect costs are less visible. Materials sent to the subcontractor need to be tracked (what was sent, when, in what quantity), and reconciled against the finished work returned. Subcontract work-in-progress is an inventory asset sitting outside your factory — often unaccounted for and uninsured. Quality inspection time on returned work is a factory labour cost directly attributable to the subcontract operation. Rework and reject costs from subcontract quality failures are frequently absorbed into general overheads rather than attributed to the specific subcontractor. Administration time — raising purchase orders, chasing deliveries, resolving invoicing discrepancies — adds management overhead per subcontractor that compounds with the number of subcontractors used. When all these costs are captured, the effective cost of subcontracting is typically 20–35% higher than the headline subcontract price.
Setting Up Subcontractor POs and Material Tracking#
Effective subcontractor management starts with treating subcontract operations like any other purchase: every job goes out on a purchase order with quantity, specification, required return date, and agreed price. Materials sent to the subcontractor are logged as a material transfer — out of your inventory and into a "materials at subcontractor" location — so your inventory records accurately reflect where your materials and WIP are at all times. When work is returned, it is received against the PO and checked against the quantity sent — any shortage or quality rejection is recorded against the PO and flagged to the subcontractor immediately. AskBiz supports this workflow through its inventory location and PO management features: subcontractors can be set up as supplier locations, and material transfers to and from subcontractors are tracked in real time.
Incoming Quality Control for Subcontracted Work#
Every item returned from a subcontractor should go through an incoming quality check before it re-enters your production flow or finished goods store. The depth of inspection depends on the criticality of the operation and the historical reliability of the subcontractor. For a well-established subcontractor with a strong track record, a sampling inspection (check 10–15% of returned items) may be sufficient. For a new subcontractor or one with recent quality problems, 100% inspection is appropriate. The incoming inspection results are recorded against the subcontract PO: quantity received, quantity accepted, quantity rejected, reason for rejection. This data accumulates into a quality performance record for each subcontractor — their rejection rate, the types of defects they generate, and their consistency over time. This data drives sourcing decisions: subcontractors with persistent quality problems can be replaced on the basis of documented performance rather than impressionistic complaints.
Subcontractor Agreements: The Clauses That Protect You#
Many SMB factories operate on informal or verbal arrangements with long-standing subcontractors. This creates legal and operational risk. A basic subcontractor agreement should specify: the specification of work (referenced to drawings, standards, or a quality standard document), the inspection and acceptance criteria, the responsibility for materials in the subcontractor's care (liability for loss or damage), the requirement to notify any process changes before implementation, the liability for defective work returned (replacement at no cost, or credit), the lead time commitment and penalties (or right to source elsewhere) for late delivery, and confidentiality covering any proprietary design information shared. These are not aggressive demands — they are standard commercial terms that professional subcontractors expect and accept. The absence of such terms leaves you exposed when problems occur.
Before and After: A UK Automotive Components Factory#
A Coventry automotive components manufacturer outsourcing heat treatment and plating to three subcontractors had no systematic tracking of subcontract POs, materials sent, or quality results. Subcontract costs were managed as a direct expense line, and quality failures were dealt with by phone call and informal resolution. After implementing AskBiz subcontractor PO management — with materials transfer tracking, incoming inspection records, and subcontractor cost allocation to specific customer jobs — three improvements materialised within six months. First, they identified that one subcontractor was short-returning parts at a rate of 1.8% (i.e., returning fewer pieces than sent), which had been invisible previously. Second, subcontractor cost per unit became visible by job, revealing that two products were being subcontracted at a cost that made them unprofitable at their current customer price. Third, a process change by their plating subcontractor was identified at incoming inspection before it caused customer-level failures — the change notified in writing per their now-formalized agreement.
Managing Multiple Subcontractors: Keeping Visibility Across the Network#
Factories using multiple subcontractors — different ones for different process types — face an additional challenge: keeping track of WIP, quality performance, and costs across a distributed network. The temptation is to manage each subcontractor informally by the relevant production manager, which creates silos and prevents factory-level visibility. A better approach is to manage all subcontractors through the same PO and materials tracking system, with a monthly review of each subcontractor's performance against three metrics: on-time return rate, quality reject rate, and cost per unit versus agreed rate. This standardised review makes it straightforward to compare subcontractors, identify the weakest performers, and have structured conversations supported by data.
Treat Subcontractors as Managed Suppliers#
The factories that get the most value from subcontracting are those that manage their subcontractors as proactively as they manage their raw material suppliers. This means systematic PO control, incoming quality inspection, performance tracking, and formal agreements. It is more work than informal management, but the payback — in avoided quality failures, recovered short-shipments, and accurate cost data — consistently exceeds the effort. AskBiz provides the PO and inventory infrastructure to manage subcontractors with the same rigour as in-house operations, without requiring specialist supply chain software. AskBiz tracks your production costs in real time. Try free at askbiz.co
People also ask
How do I track subcontractor costs in a factory?
The direct cost of subcontracting — the price charged by the subcontractor — is visible on every invoice. The indirect costs are less visible.
What should a subcontractor agreement include for manufacturing?
Effective subcontractor management starts with treating subcontract operations like any other purchase: every job goes out on a purchase order with quantity, specification, required return date, and agreed price.
How do I manage quality control on outsourced work?
Every item returned from a subcontractor should go through an incoming quality check before it re-enters your production flow or finished goods store. The depth of inspection depends on the criticality of the operation and the historical reliability of the subcontractor.
How do I track materials sent to a subcontractor?
Many SMB factories operate on informal or verbal arrangements with long-standing subcontractors. This creates legal and operational risk.
What is the true cost of using manufacturing subcontractors?
A Coventry automotive components manufacturer outsourcing heat treatment and plating to three subcontractors had no systematic tracking of subcontract POs, materials sent, or quality results.
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