# Trade-Off Curves

**URL:** https://kaizumi.com/dictionary/trade-off-curves

**Description:** Trade-off curves document the relationships between design parameters, showing how improving one attribute affects others.

**Category:** lean-tools

**Tags:** advanced, metrics

## Definition

Trade-off curves are graphical representations of the relationships between design parameters, showing how improving one attribute affects others. For example, a trade-off curve might show how battery weight affects vehicle range, or how wall thickness affects both part strength and material cost. These curves capture engineering knowledge in reusable form, enabling set-based concurrent engineering by showing which design spaces are feasible and where the optimal balance lies. Trade-off curves prevent reinventing knowledge on each project and enable faster, better-informed decisions.

## Examples

### Automotive

> Toyota maintains trade-off curves showing the relationship between engine weight and fuel economy across different engine families. When developing a new vehicle, the chief engineer can immediately see what weight reduction is needed to achieve a fuel economy target, without starting analysis from scratch.

### Manufacturing

> A machining operation has trade-off curves relating cutting speed, tool life, and surface finish. When a new part requires specific surface finish, engineers can immediately identify the feasible range of cutting speeds and expected tool life—knowledge captured from years of experience.

### Product Design

> A consumer electronics company maintains trade-off curves for battery capacity versus device thickness and weight. Product designers can immediately see what's feasible: a certain battery life requires a minimum thickness. This prevents infeasible concepts and focuses effort on achievable designs.

## Key Points

- Capture engineering knowledge in reusable, visual form
- Enable set-based decisions by showing feasible design space
- Prevent repeating analysis for known relationships
- Must be maintained and updated as technology advances

## Common Misconceptions

**Trade-off curves are just engineering data.** They're strategic assets that enable faster development. Organizations that capture and maintain trade-off knowledge outpace those that rediscover it each project.

**Once created, trade-off curves are permanent.** Technology changes shift the curves. Material advances, manufacturing improvements, and design innovations require updating trade-off knowledge.

## See Also

- [A3 Problem Solving](/dictionary/a3-problem-solving) - Tool for capturing trade-off analysis

Source: https://kaizumi.com/dictionary/trade-off-curves
Licence: free to quote and cite with attribution to Kaizumi.