You’re getting downvoted because you may have missed my point. To clarify for your sake, once you have hardware in the loop (eg mechanical engineers designing

You’re getting downvoted because you may have missed my point. To clarify for your sake, once you have hardware in the loop (eg mechanical engineers designing things, manufacturing scaling for production) and a large commercial organization who needs to be ready for a product launch, you need a waterfall type plan. Agile principles (customer focus, respond to change) can apply, and you can break up the work into 2 weeks, but you do need to look past the next 2-4 weeks and know where things are planned. Commitments matter in the $millions. Software-only SAAS has the luxury of avoiding that complexity.