I've found it's useful to think of it through a lens of "expectations." The organization that pays me money (my place of work) has a set of goals it wants to achieve. In order to achieve those goals it hires representatives (my boss, his boss, etc.) to orchestrate the achievement of those goals. So now I am hired to help move those goals forward, and in return I am compensated with money.

However, an organization's goals, and its expectations of what it can and requires to achieve, as well as how long it will take, are dynamic. That means its representatives decide what those goals are. If I can convince my boss/skip/what-have-you that certain goals will require more time and more resources, then I can stretch their expectations into the future in such a way that they benefit my ends.

So long as my boss's expectations are met, then I am "getting the job done."

No different than if my boss decides to press screws into my thumbs on another "top priority project that needs to be done ASAP" to put pressure on me so that he can achieve his goals.

So perhaps a better way to measure productivity -- if we are to put a word to it -- is from the age-old intuitive standpoint: does it feel like we are moving closer to, and achieving, our goals? I think an approach any more concrete or systematic than that is just a tool for gaining leverage in the aforementioned negotiations.