You've probably tried to be more productive at some point. If you aren't getting the output you want for the effort you put in, then it makes sense to look at ways to improve your productivity.So you can try;
- Being more organised
- Managing your time better
- Setting goals and deadlines
- Optimising your processes
There are countless systems and tools to help you do these things, and all of them work. Or, at least, all of them work sometimes.
If you've tried increasing your productivity using any of the above, you probably found that you got an initial boost but then slipped back into your usual habits. This can lead you to the conclusion that you are the problem, rather than the system (after all, the system worked while you stuck to it).
But usually it's neither you nor the system that's the problem, it's just that you're using the wrong tool at the wrong time.
The language of productivity
Much of the terminology we use when we talk about productivity, and indeed the very concept of productivity, comes from industry.
When you have a production line, you want to have as efficient a system as possible. You will have production targets, schedules and procedures to make sure the output consistently meets demand.
To achieve this, you need a well-defined, repetitive production process. It's about following the steps consistently and getting the job done.
But productivity is not enough. If there's a problem somewhere in the production line, or if you want to develop something new, you need to get creative.

Productivity and creativity take different approaches
Creativity is often inefficient. It requires open and playful exploration of a variety of ideas, many of which you will never use. It is difficult to set targets because you don't know how it's going to work out and some of the things you try might fail.
Creativity is the opposite of productivity, but is essential as a precursor.
Although it is difficult to quantify the output of creative time - because it doesn't produce immediately measurable results - many companies still recognise its value. 3M, the company behind post-it notes and scotch tape, developed a "15% time" rule, where their R&D staff could spend 15% of their time working on anything they liked, without the pressure to "produce". Google took concept this a step further, with "20% time".
There is a lot of creativity in the design of, say, an iPhone; many of the ideas the design team consider will never go to market. But then following that experimentation comes the creatively constrained phase of production- you don't want someone on the assembly line of your iPhone expressing their creative urges.
How this applies to PhD work
When you are writing your thesis, if you are 2 months away from submitting then you should be focused on productivity, with the clear goal of getting the thing finished on time.
This means that you should not be spending much time exploring new ideas, but rather consolidating the ones you have already explored in depth.
At earlier stages, you should explore dead ends, waste time daydreaming, take risks and make as many mistakes as possible, and be less focused on rigid productivity.
See also: Your final PhD year: Moving towards completion
Productivity comes last
Productivity systems and tools are useful, but only when applied at the right time.
Because research so often requires finding creative solutions to difficult problems, we need to give equal consideration to the skills of creativity, letting go of the rigid timetable-and-goal-oriented approach, and taking time to play. It's only once you've done that exploration that it's time to narrow your focus and get productive.