The idiom "back to the drawing board" means that you need to start over again because your previous plan or idea did not work out as expected. It is often used when something has failed or did not go according to plan, and you need to come up with a new strategy or solution.
For example, imagine you and your team have been working on a project for weeks, but when you present it to your boss, they don't like it. Your boss might say, "Sorry, guys, it's back to the drawing board for this one. We need to come up with a new plan."
Another example could be when you are trying to solve a problem, but the solution you thought would work doesn't. You might say, "Well, that didn't work. Back to the drawing board."
In short, "back to the drawing board" means to start over and come up with a new plan or idea when the previous one didn't work out.
• My cake was burnt, back to the drawing board for me.
• We failed to win the game, so it's back to the drawing board for our team.
• Our new product design was rejected, and we have to go back to the drawing board.
• The first draft of my novel was not good enough, so I had to go back to the drawing board and rewrite it.
• The company's marketing strategy didn't work, and they had to go back to the drawing board and come up with a new plan.
• After the failed experiment, the scientists had to go back to the drawing board and rethink their hypothesis.