Every procurement team makes make-or-buy decisions. Almost none has a framework for them. The decision to insource or outsource a category, a process, or a component is the highest-stakes sourcing choice most organizations face. Get it wrong in one direction and you bleed margin through inflated external costs for years. Get it wrong in the other and you carry fixed overhead for a capability you should have bought off the shelf.
Yet when you ask most procurement leaders to describe their make-or-buy methodology, the answer is uncomfortable silence. Then something about "we evaluate case by case." Which means each decision invents its own analytical standard. Two identical categories can land on opposite sides of the insource/outsource line depending on which analyst ran the numbers and which stakeholder shouted loudest.
The cost comparison almost everyone gets wrong
The most common error is structural, not arithmetic. Teams compare the internal incremental cost — materials and direct labor — against the supplier's full price. This comparison systematically understates the true cost of internal production because it excludes allocated overhead, quality management, coordination time, and engineering support. Insourcing wins the spreadsheet battle every time, even when it shouldn't.
The reverse error is equally damaging. When evaluating whether to outsource, teams often fail to strip out fixed costs that won't disappear after the transition. That factory space? You're still paying the lease. Those quality engineers? They're reassigned, not eliminated. The "savings" from outsourcing vanish into a P&L line that never actually shrinks.
Procurement research confirms this pattern. Reviews of make-or-buy practice find that organizations "which still make their sourcing decisions based only on cost will eventually die" — but cost remains the dominant determinant in most firms. The same analysis notes that strategic factors like capability retention, supply market depth, and switching costs are "systematically underweighted."
What happens without a framework: ad-hoc decisions that compound
Without a systematic methodology, make-or-buy decisions become reactive. A supplier raises prices by 8% and suddenly every category looks like an insourcing candidate. A new CFO demands headcount reduction and outsourcing becomes the universal answer. The decision quality is determined by the trigger event, not by the underlying economics of each category.
Research on outsourcing decision-making finds that many firms — especially mid-market organizations — lack the expertise to evaluate these choices systematically. The result: decisions that are "highly uncertain and often ad-hoc." Supply chain researchers have noted that deeper-tier sourcing decisions are frequently made via "reactive, arbitrary measures devoid of a systematic approach." New structured frameworks have only recently begun to emerge.
The compounding effect is what makes this dangerous. A single bad make-or-buy decision on a $3M category costs maybe $300K–600K per year. Ten such decisions across the procurement portfolio, each made under a different analytical standard, costs several million annually — with no single decision large enough to trigger a post-mortem. The losses are distributed, invisible, and permanent.
The five-factor framework most teams are missing
A defensible make-or-buy framework evaluates five dimensions, not one. Each dimension gets a score. Categories with consistently high scores across all five dimensions are strong outsourcing candidates. Categories that score high on strategic importance and low on supply market depth stay internal.
The fifth factor — and the one most frameworks ignore — is decision reversibility. A make-or-buy choice on a standard IT service with multiple providers and short contract terms can be reversed in months. A decision on a specialized manufacturing process with tooling investments, regulatory approvals, and multi-year qualification cycles is effectively permanent. The framework should assign higher scrutiny to irreversible decisions regardless of how the cost comparison looks.
What this means in practice
Three changes separate organizations that get make-or-buy right from those that drift into it:
- Standardize the cost comparison. Every make-or-buy analysis uses the same cost template: full internal cost (including allocated overhead, quality, coordination) vs. full external cost (including logistics, inspection, relationship management). No analyst gets to define their own denominator.
- Score all five factors before the numbers. Run the strategic assessment — capability criticality, market depth, switching costs, reversibility — before anyone opens a spreadsheet. Make-or-buy is not a cost decision that strategy informs. It is a strategy decision that cost informs.
- Review every decision at 12 months. The analysis that justified outsourcing three years ago may not hold today. Supply markets shift. Internal capabilities erode or strengthen. An annual review on every make-or-buy decision — all of them, not just the big ones — catches drift before it becomes structural.
Why do most make-or-buy decisions go wrong in procurement?
Most organizations lack a systematic framework, comparing internal incremental cost (materials and direct labor only) against the full supplier price. This misses fixed overhead that won't disappear after outsourcing and strategic capabilities that take years to rebuild. Without a structured methodology, decisions default to whichever side builds the more persuasive spreadsheet.
What is the most common error in make-or-buy analysis?
Comparing internal incremental cost against full external price. This systematically understates the true internal cost — because it excludes allocated overhead, quality management, and coordination expenses — making insourcing look artificially cheaper. Separately, many teams fail to strip out fixed costs that won't disappear after outsourcing, distorting the comparison in both directions.
What should a procurement make-or-buy framework include?
A robust framework goes beyond unit cost to evaluate: total landed cost (including logistics, quality, and coordination), strategic capability retention (core vs. commodity activities), supply market depth (how many viable alternatives exist), switching costs (both to outsource and to reverse the decision), and risk factors specific to the category — single-source dependency, IP exposure, and regulatory constraints.