Focusing attention holistically on a whole  process, end to end, and the productivity of the process will improve, improving the outcome.

When you focus just on the outcome, all you get is the opportunity to improve the efficiency of the existing process, but it will have no sustainable impact on the productivity of the process itself, and inevitably when you just focus on efficiency of one part, over time the whole process  will at the very best, remain at the stable level, because as you make efficiency improvements in one spot, in another, something has gone wrong to reduce the efficiency of that point in the process.

If you want to improve, focus on the whole process, not pieces of it.