Park for a moment the regular confusion between efficiency and effectiveness, the one that can create mindblocks in rapid iteration is the Minimum Viable Product.
I have heard this used interchangeably for paper sketches in Design Thinking creative sessions, all the way through to the first product being taken to the actual market at production scale.
Mindblocks - well not having a clear view of this makes it very difficult to understand what each rapid iteration cycle is trying to achieve.
I have become used to using MVP as something that may better be called the Minimum Learning Vehicle (MLV). I say it may better be called that because I think it better reflects the learning discipline of the MVP:
1. Identify what it is you want to learn from this iteration.
2. Draw/make/build only that which will give you that learning.
3. Test with the end user.
By its nature, the use of MLVs keeps things lean - avoiding scope creep and maintaining focus on the value proposition (the value to the end user).
It's a critical thing for all parties to agree when they set out to iterate to value at speed.
What do you call your MLV?