Generally people just get a feel for it from practical experience, but there are some thought exercises you can use to help. For example "What if two programs

Generally people just get a feel for it from practical experience, but there are some thought exercises you can use to help. For example "What if two programs did this?": https://devblogs.microsoft.com/oldnewthing/20050607-00/?p=35413 https://devblogs.microsoft.com/oldnewthing/20050607-00/?p=35... Often people with a poor grasp of complex systems will make a naive suggestion like "if x fails, we can retry n times". In isolation, this makes sense, although it adds complexity. In the grand scheme of things, it doesn't make sense, because if x does y, and y has a failure and retries... and then y does z, and z has an failure and retries, well now you have x * y * z retries all multiplying out and you won't hit your top-level "n times" restriction until after the heat death of the universe. With a bit of practice, you can spot and point out these kinds of things.