What is the First Step of the Engineering Design Process

What two things determine whether or not engineering solutions are successful?

During which step of the Design Process do you experiment with the prototype under controlled conditions and collect /record data?

Which step of the Design Process involves communicating the results of your tests

If your initial design doesn't fully solve the problem or meet the challenge, you must go back and revise your plan. This is part of which step in the Design Process?

Which answer (or answers) best describes criteria?