‘Like clockwork’ means ‘perfectly; exactly as planned; no delays or problems’. Clocks have a lot of moving parts that must all work together to be perfectly correct. When a project runs ‘like clockwork’ everything happens on time and correctly. This is a positive expression. As an example, ‘I love the Tokyo railway system. There are so many people in Tokyo, but the trains are almost always on time. It’s like clockwork.
A: That was the best presentation!
B: It was great, hey? It was like clockwork.
A: So far, everything with this project is running like clockwork.
B: Great. Keep it up and we can finish by the end of the month.
Is your day running like clockwork today?