Back to the drawing board
Start again on a new design or plan after the failure of an earlier attempt.
This term has been used since WWII as a jocular acceptance that a design has failed and that a new one is needed. It gained common currency quite quickly and began appearing in US newspapers by 1947, as here in the Walla Walla Union-Bulletin, Washington, December 1947:
"Grid injuries for the season now closing suggest anew that nature get back to the drawing board, as the human knee is not only nothing to look at but also a piece of bum engineering."
It was well-enough known by 1966 for it to be used as a title for an episode in the 'Get Smart' TV series, and has also been used as the title of several books.
A drawing board is, of course, an architect's or draughtsman's table, used for the preparation of designs or blueprints.
The phrase originated as the caption to a cartoon produced by Peter Arno (Curtis Arnoux Peters, Jr.), for the New Yorker magazine, in 1941. The cartoon shows various military men and ground crew racing toward a crashed plane, and a designer, with a roll of plans under his arm, walking away saying, "Well, back to the old drawing board".