Think first and do first Strategies

If the environment is changing so much, can a system plan and execute?

The idea would be do, give prominence to DO FIRST, while doing that to see and think, giving feedback to the DO. Sounds similar (all those in scum)?

This is what we do in Scrum - time boxed delivery and at the end of it do a retrospective giving feedback to the next time boxed.

DO FIRST? really in scrum ? - we do a lot, lets do and see, lets try it out - thats whats promoted in Scrum.