[SKILNER]

What this completely overlooks is the time developers spend trying to understand existing code. For greenfield development that is close to zero. For maintenance work it is over half of their time and arguably the most difficult work in software engineering. Maintenance work in complex systems is far more challenging than developing new complex systems.

Some people, not many, take software maintenance seriously and conduct studies on it - in the study at the link below they point out that comprehending existing code took on average 57% of developer's time. Actual editing consumed 5%.

And software maintenance is no different - think again.

https://www.researchgate.net/publication/318811113_Measuring...