"The first 90% of a development is done in the first 10% of your estimated time schedule and the last 10% is done in the remaining time"

"The first 90 percent of the code accounts for the first 90 percent of the development time. The remaining 10 percent of the code accounts for the other 90 percent of the development time."

It's called the 90-90 rule. Is this what you're trying to say?

I basically said that with a few other words, however your description accounts for 180% time all in all 😂

@Nilsen02 I copy pasted the quote from Wikipedia actually

@hashris Well then Wikipedia has some issues with time 😂 both phrases ends with stating it takes 90 percent development time.
All this aside. A former co-worker if mine told me this, and it sure held up to its promise during our work.