Operating system Quote by Frederick P. Brooks Jr
““Because ease of use is the purpose, this ratio of function to conceptual complexity is the ultimate test of system design. Neither function alone nor simplicity alone defines a good design. This point is widely misunderstood. Operating System/360 is hailed by its builders as the finest ever built, because it indisputably has the most function. Function, and not simplicity, has always been the measure of excellence for its designers. On the other hand, the Time-Sharing System for the PDP-10 is hailed by its builders as the finest, because of its simplicity and the spareness of its concepts. By any measure, however, its function is not even in the same class as that of OS/360. As soon as ease of use is held up as the criterion, each of these is seen to be unbalanced, reaching for only half of the true goal.””
About This Quote
Source Book: The Mythical Man‑Month, 1975
Design quality requires balancing functional richness with conceptual simplicity; neither alone defines excellence.
In simple terms: Good design mixes many features with easy use.
Key Takeaway
Aim for both power and simplicity in design.
Themes
design
functionality
usability
complexity
balance
Mood
analytical
thoughtful
Type
technical
educational
When to use this quote
- software development
- product design
- user experience
- engineering education
Key Concepts
Systems engineering
human‑centered design
Questions to Reflect On
- How do you measure functional vs. simple trade‑offs?
- What design processes ensure balance?
A Different Perspective
Overemphasis on one aspect can lead to impractical systems.
![“Lehman and Belady have studied the history of successive releases in a large operating system.[6] They find that the total number of modules increases linearly with release number, but that the number of modules affected increases exponentially with release number. All repairs tend to destroy the…” quote by Frederick P. Brooks Jr](https://sms4smile.com/quotes/img-quotes/115/frederick-p-brooks-jr-11230_history_lehman-and-belady-have-studied-the-histo_145780.jpg)
