A complex system that works is invariably found to have evolved from a simple system that worked. A complex system designed from scratch never works … - John Gall

A complex system that works is invariably found to have evolved from a simple system that works. The inverse proposition also appears to be true: A complex system designed from scratch never works and cannot be made to work.

A COMPLEX SYSTEM THAT WORKS IS INVARIABLY FOUND TO HAVE EVOLVED FROM A SIMPLE SYSTEM THAT WORKED. A

IN ORDER TO REMAIN UNCHANGED, THE SYSTEM MUST CHANGE Specifically,

The field of Architecture has given rise to a second major principle relating to the Life Cycle of Systems. This principle has emerged from the observation that temporary buildings erected to house Navy personnel in World War I continued to see yeoman service in World War II as well as in subsequent ventures, and are now a permanent, if fading, feature of Constitution Avenue in Washington... We conclude: A temporary patch will very likely be permanent.

A selective process goes on, whereby systems attract and keep those people whose attributes are such as to make them adapted to life in the system: Systems attract systems-people.