Assumptions and method

When to be cautious

Include comparable quality, transition, oversight and exit costs before deciding. A cost advantage is not a sourcing strategy.

Make = fixed + variable × units; buy = price × units

Test a scenario

Use your own inputs

Inputs stay in your browser. Shared scenario links include your inputs.

Use the result in a decision

Use the same scope and test commercial assumptions.

Include comparable quality, transition, oversight and exit costs before deciding. A cost advantage is not a sourcing strategy.

Set a baseline and change one assumption to compare outcomes.

A worked example

Follow the fixed teaching example
  1. Make cost = 15,000 + 30 × 800 = 39,000; buy cost = 55 × 800 = 44,000.
  2. The modelled cost advantage of making is 5,000. The crossover is 15,000/(55 − 30) = 600 units.

These illustrative inputs describe a project scenario, not a published benchmark. All monetary inputs use the same currency and price basis.

Fixed cost of making
15000
Variable make cost per unit
30
Buy price per unit
55
Required units
800
Make cost
39,000
Buy cost
44,000
Cost advantage of making
5,000
Crossover quantity
600 units

Interpret the output only within the assumptions above. Changing the inputs changes the result; it does not validate the inputs.

Source & credit

Standard estimating practice; the cited guide documents use rather than claiming invention.

GAO: Cost Estimating and Assessment Guide

This is independently written code and explanation of the underlying method. The linked publication, its diagrams and its trademarks remain its owner’s material; no permission to reuse them is implied.

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