Seventy percent of organizations have brought previously outsourced work back in-house over the past five years, according to Deloitte's 2024 Global Outsourcing Survey. The primary reason is not supplier failure. It is that the original make-vs-buy analysis was built on the wrong numbers. Comparing marginal internal cost to fully loaded supplier price is the single most pervasive and costly error in procurement decision-making. This framework replaces that error with a structured, five-factor decision process.
The variables that matter
Make-vs-buy decisions involve five factors. Weight them explicitly. The weighting prevents the most common failure mode: cost-only analysis that ignores strategic consequences.
The variables that seem to matter but do not
Sunk costs have zero place in make-vs-buy analysis. Equipment already purchased, facilities already built, training already completed — these costs exist regardless of the decision. Only future incremental costs and opportunity costs of existing assets matter. AuraVMS documents this as a recurring error: organizations include past capital expenditure in their make-cost calculation, which systematically biases the analysis toward insourcing.
Ideological preference is the second phantom variable. Some organizations reflexively insource because they have the capacity. Others reflexively outsource because lean operations is the stated strategy. Neither reflex produces correct decisions. Each specific activity must be analyzed on its own economics and strategic fit. The Deloitte finding that 78% of organizations now operate their own offshore centers alongside outsourcing relationships confirms the direction: most procurement organizations land somewhere in the middle, not at either extreme.
The decision logic
Run each candidate activity through a five-step evaluation. The steps are sequential: a failure at any step stops the analysis and produces a clear answer.
Step 1: Strategic filter. Is this activity core to competitive advantage or customer perception? If yes, the decision defaults to make. Strategic insourcing requires ongoing investment to maintain capability; do not insource and then starve the operation of capital. If no, proceed to step 2.
Step 2: Full-cost comparison. Build total cost of ownership for both make and buy scenarios. Use the cost categories above. This is where most organizations fail: they compare incremental internal cost to fully loaded external price. The fix is simple in principle and difficult in practice. It requires accounting for overhead allocation, quality cost, inventory carrying cost, and management overhead on both sides. If internal TCO is lower by 10% or more, make. If external TCO is lower by 10% or more, buy. Within 10%, the decision hinges on steps 3-5.
Step 3: Risk assessment. For the make scenario: do you have the capacity, the skilled workforce, and the management bandwidth? For the buy scenario: how concentrated is the supplier market? What is the geopolitical exposure? What is the cost of a supply disruption in dollars per day? Assign a risk premium to the higher-risk option.
Step 4: Transition feasibility. What does it cost to switch? Supplier qualification, tooling transfer, pilot runs, training, system integration. A make-vs-buy analysis that produces a 5% savings but ignores a $400,000 transition cost is wrong. Discount the projected savings by the transition cost amortized over the expected duration of the arrangement.
Step 5: Reversibility check. If you are wrong, how expensive is the reversal? Internal production that is shut down takes 12-18 months to restart. External sourcing contracts have termination penalties. Prefer the option with the lower cost of being wrong, all else equal.
Worked example: machined component for industrial equipment
A mid-market manufacturer evaluates whether to make or buy a precision-machined housing component. Annual volume is 12,000 units. The internal cost estimate is $48 per unit (materials $22, labor $16, machine time $6, overhead $4). An external supplier quotes $52 per unit fully delivered. At face value, making saves $48,000 per year.
The corrected analysis adds the hidden costs. Internal production requires $180,000 in new CNC equipment amortized over five years ($36,000 per year, or $3 per unit). Quality inspection and rework for this component run 2.1% of production cost ($1.01 per unit). Inventory carrying cost on raw materials and WIP at 18% annual carrying cost adds $1.73 per unit. Corrected internal cost: $53.74 per unit. The supplier quote at $52 per unit with a 0.4% historical defect rate, guaranteed 5-day lead time, and zero capital outlay becomes the correct decision. The original $48,000 savings was a $20,880 annual loss disguised by incomplete cost accounting.
The most common failure: cost-only mandates that erode competitive advantage
Pure cost minimization systematically outsources the capabilities that made the organization successful. Procurement KPIs focused exclusively on unit price incentivize outsourcing everything that is cheaper externally. Over time, the organization retains only the activities no supplier wants. This is not a hypothetical concern. Cost reduction as the primary outsourcing driver fell from 70% in 2020 to 34% in 2024, per Deloitte data cited by DoIT Software. Talent access, strategic resilience, and supply security are now weighted more heavily than pure cost savings.
Gartner predicted that 60% of finance and accounting outsourcing contracts would not be renewed by 2025 due to outdated pricing models that failed to drive digitization and process improvement. The same pattern applies across procurement categories. An outsourcing decision built on a cost comparison that ignores quality, risk, and strategic trajectory is likely to be reversed within five years.
What correct execution produces
Organizations that apply a weighted, multi-factor make-vs-buy framework produce fewer reversals, lower total cost, and decisions that hold up under strategic review. McKinsey reports that companies using advanced strategic sourcing including clean-sheet should-cost modeling achieve 10-20% savings for many categories. The savings come from correctly identifying which activities belong inside the organization, not from squeezing suppliers on price alone.
Operational checklist
- Audit your last three make-vs-buy decisions. Pull the original cost comparison. Did it use marginal internal cost or fully loaded cost on both sides? If marginal, recalculate.
- For your top three outsourced activities by spend, verify the decision was made on multi-factor analysis, not cost alone. If cost-only, run the five-factor framework on each.
- Identify one activity currently outsourced that could plausibly be a core competency. Run the strategic filter. If it passes, commission a full make-vs-buy analysis.
- For any activity outsourced more than three years ago, schedule a formal review. Market conditions, supplier capabilities, and internal capacity all shift on roughly this timeline.
- Add transition cost and reversibility cost as explicit line items in every future make-vs-buy business case. These are the two costs most frequently omitted.
- Document one outsourcing decision your organization has reversed. Identify which factor was mispriced in the original analysis. Use this as a calibration case for future decisions.
Data sources
- Deloitte — 2024 Global Outsourcing Survey. Accessed June 29, 2026.
- SupplyChainMath — Make vs Buy Decision Framework. Accessed June 29, 2026.
- McKinsey — Building Superior Capabilities for Strategic Sourcing. Accessed June 29, 2026.
- DoIT Software — Outsourcing Statistics (aggregating Deloitte, Gartner, KPMG). Accessed June 29, 2026.
- AuraVMS — Make vs Buy Decision in Procurement (2026). Accessed June 29, 2026.
- Umbrex — McKinsey Eight-Step Sourcing Framework. Accessed June 29, 2026.
- Gartner — F&A Outsourcing Contract Non-Renewal Prediction (May 2021). Accessed June 29, 2026.
What is the most common make-vs-buy decision error?
Comparing marginal internal cost to fully loaded supplier price. Internal costs are calculated incrementally (labor + materials only) while supplier prices include overhead, margin, logistics, and compliance. Always compare full cost to full cost.
When should a company never outsource?
When the activity is critical to product success or customer perception, requires specialized skills with very limited suppliers, or fits within a core competency the firm needs to develop for competitive advantage. These are the Quinn and Hilmer criteria.
How often should make-vs-buy decisions be reviewed?
Major outsourced activities every 3-5 years. More frequently when there are new market entrants, technology shifts, demand pattern changes, or strategic repositioning. 70% of firms have reversed prior decisions since 2020.
What are hybrid make-vs-buy models?
Make-to-stock with buy-on-surge for peak demand, make final assembly while buying components, dual sourcing (60% internal, 40% external), contract manufacturing with retained IP, and tolling where you provide materials and the supplier provides processing.