I’m a big fan of setting constraints to get work done. If you make work a scarcer quantity, you’re more likely to use time wisely and get things done than if it feels like an endless to-do list.
There’s two key ways you can do this: restrict your hours or restrict your workload.
Restricting hours is fairly simple: set aside a certain chunk of time for work and don’t work outside of it. This is a commonly advocated productivity method, from Cal Newport’s fixed-schedule productivity  to Pomodoro ’s for working in short bursts of time.
Restricting workload changes the equation. Instead of deciding on a set number of hours, you decide on a set number of tasks. You might decide to create a list of tasks for the day and keep working until you can get them finished. It also applies on shorter timescales when you might decide not to work until you get to a particular milestone and then call it quits.
I’ve gone back and forth over using both types of constraints over the years. This suggests to me that neither is a dominant strategy (better in all situations) but that both have their usefulness with different productivity problems.
When Should You Constrain Time?
The biggest advantage of constraining time is that it’s always unambiguous. If you decide to work for three hours and then stop, there’s no confusion there. On the other hand, if you decide to work until you’re finished an essay, there’s the chance that it might be done in twenty minutes or take three weeks.
This lack of ambiguity means that the constraint rarely fails because you were overly optimistic. It’s a lot easier to predict working a set number of hours than working until you complete a set number of tasks.
However, I’ve also found time constraints can encourage a sloppier attitude towards work. You might decide to spend all day studying in the library—but without tasks to constrain your productivity, you end up checking your phone or skipping hard problems to work on easier stuff.
My rule of thumb is that time constraints work best when:
- It’s unclear the time and effort required to complete the task.
- The work itself is ambiguous, and may require a lot of trial-and-error.
- The work is continuous and can’t be easily divided into discrete chunks.
I tended to use this method during my ultralearning  projects, because they often had long stretches of continuous work where it would be unclear how much time would be required.
When Should You Constrain Tasks?
The advantage of constraining tasks is that it focuses directly on the object of productivity: whatever you’re trying to accomplish. Done successfully, this means that it’s very hard to fool yourself into believing you’re working hard but you’re not actually accomplishing much.
The drawback of this approach is that tasks can often be ambiguous or hard to predict. If you fail to predict properly you might create to-do lists which are unachievable or those that are trivial. This can create more variability in your schedule, resulting in days when you finish everything quickly and days when you can’t finish it all.
I’ve found task constraints work best under the following conditions:
- Tasks are discrete and fairly predictable.
- You might be tempted to fill up time without making real progress
- The tasks are frequently repeated, and therefore easier to estimate.
I’ve tended to opt for this method with a lot of my business and writing work. They tend to form discrete tasks that are fairly easy to anticipate how long they will take. Constraining the tasks encourages me to get them done quickly, with minimal delay and procrastination.
What Constraint Should You Use?
I find myself flipping back and forth between the two constraints. I tend to use task constraints as my default, since much of my daily life is filled with the small, repeatable tasks that are well-handled by that system. But I switch to having chunks of time for particular projects when it’s clear I’m not getting much done just setting up the tasks.
What do you use to control your productivity? Do you prefer making to-do lists and focusing on tasks? Or do you prefer to set a schedule and focus on hours invested? Share your thoughts in the comments.