Operations Strategy & Sourcing Lab

Make vs. Buy Decision Lab

Evaluate in-house manufacturing vs. supplier procurement, crossover indifference volumes, and landed unit costs.

Cost Model Volume Sensitivity Sourcing Theory FAQ

Industry Presets

Load calibrated manufacturing models.

Step 1: Production Volume & Cost Structures

In-House (Make) vs. Supplier (Buy) Parameters

Units
Projected annual component demand quantity.

1. In-House Manufacturing (Make)

$
$
$
Machining power, tooling wear & scrap.
$
Tooling amortization, lease & supervision.

2. Supplier Procurement (Buy)

$
$
$
Receiving QC, defect sorting & return costs.
$
Vendor audits, legal & procurement admin.
Total Cost to Make
$0
$0.00 / unit
Total Cost to Buy
$0
$0.00 / unit
Net Cost Advantage
$0
Evaluating...
Crossover Indifference (Q*)
0 Units
Volume where Make = Buy cost

Step 2: Volume Sensitivity Matrix

Total Costs Across Volume Scenarios

Demonstrates how operating leverage flips the optimal choice between fixed overhead amortization and vendor unit variable costs.

Demand Scenario Total Cost (Make) Total Cost (Buy) Optimal Choice Cost Savings ($)

Strategic Sourcing Guide

Understanding make vs. buy tradeoffs

The make or buy decision is an essential strategic choice balancing operating leverage, supplier risk, and proprietary intellectual property.

  • Operating Leverage: In-house production carries high fixed tooling costs but low unit variable costs. High volume amortizes fixed costs, making production cheaper per unit.
  • Flexibility & Low Volume: Purchasing from suppliers avoids capital lockup and fixed overhead risks, ideal for uncertain or low-volume components.
  • Non-Financial Factors: Lead-time agility, supply chain security, quality assurance, and core competency focus often outweigh marginal cost savings.

Explore multi-criteria tradeoffs in the Strategic Decision Matrix Lab.

Managerial Accounting Formulas

Essential make vs. buy formulas

Total Cost (Make) = Fixed Overhead + (Unit Variable Cost × Volume)

Total Cost (Buy) = Sourcing Overhead + (Landed Purchase Cost × Volume)

Crossover Q* = (Make Fixed − Buy Fixed) ÷ (Buy Landed − Make Variable)

Unitized Cost = Total Cost ÷ Production Volume

Net Advantage = Total Cost (Buy) − Total Cost (Make)

Model project risk and return in the Scenario Planning Lab.

FAQ

Make vs. buy decision questions

How is the make vs. buy crossover indifference volume calculated?

Crossover Volume Q* = (Fixed Cost of Making − Sourcing Fixed Overhead of Buying) ÷ (Unit Landed Purchase Cost of Buying − Unit Variable Cost of Making). Above Q*, making in-house is cheaper; below Q*, buying from suppliers is cheaper.

What costs should be included in the 'Make' cost structure?

Only relevant incremental costs: direct materials, direct labor, variable utilities/machining overhead, and dedicated incremental tooling/equipment depreciation. Avoid allocating unrelated corporate overhead.

What costs should be included in the 'Buy' cost structure?

The supplier's quoted purchase price plus landed logistics expenses: inbound freight, customs/tariffs, quality incoming inspection, and vendor management overhead.

What qualitative strategic risks affect the make or buy choice?

Intellectual property protection, supplier supply chain reliability, lead-time flexibility, quality assurance control, and plant capacity opportunity costs often override pure cost differences.

Can I export sensitivity volume schedules and cost breakdowns to CSV?

Yes. You can export complete unitized costs, fixed expense schedules, crossover volume calculations, and multi-tier volume sensitivity tables as a UTF-8 CSV spreadsheet with formula injection defense or print an executive brief.

Is this tool certified manufacturing consultancy or procurement audit advice?

No. This tool provides educational operations management and strategic sourcing models for business training without commercial manufacturing engineering or procurement audit guarantees.

Continue Exploring Strategy & Operations Tools

Explore our Strategy & Decision-Making Hub, balance multi-attribute tradeoffs in the Decision Matrix Lab, model uncertainty in the Scenario Planning Lab, or evaluate capital equipment in the Lease vs. Buy Lab.