Simplicity Requires Trade-offs

Definition

Simplicity is not free. A system that tries to be comprehensive, perfect, or all things to all people will be complex. Rule 9 states: "You need to be prepared to trade off other values for simplicity. A system that seeks to be totally comprehensive may be very complex. You may need to trade off that comprehensiveness for simplicity."

In the Book

De Bono illustrates this throughout the book. "Simplicity very often involves the 'trading-off' of one value against another." He emphasizes: "If simplicity is a real value then you must be prepared to trade off other real values in order to gain simplicity."

One example: toll roads. A non-stop electronic toll system that uses transponders and sends bills is much simpler to operate than stopping every car and collecting cash. But it creates complexity for drivers who must obtain and manage a transponder. Another example: forms designed for the user's convenience may add complexity for the data processor.

De Bono notes that a system seeking zero error rates may require so much redundancy and checking that it becomes vastly more complex. "So long as errors remain unacceptable, you may need to trade off perfection for practical simplicity. Then you design a parallel system to deal with the exceptional cases."

He observes that this applies even to modular design: breaking a system into smaller units simplifies each unit but may add coordination complexity. "Breaking things down into smaller units, decentralization and modular design are all approaches to simplicity—so long as the unity of the overall purpose is not lost."

The key insight: "It is usually not possible to have everything, so there has to be a choice between different values. It is important to be deliberate and conscious of the choices that are being made."

Why It Matters

This concept is crucial because it prevents false simplicity. Many "simple" designs are simple on the surface but hide complexity elsewhere or fail some other value. By explicitly naming what you are trading off—comprehensiveness, precision, variety, ease of maintenance—you avoid pretending simplicity is free. This forces honest design conversations: what matters most here? What are we willing to give up?