Actions to Take: Every time you assign a discrete task, attach a deadline with a specific date. Do this even for tasks that don't "need" a deadline.
Most bosses do not set deadlines for most things. Some avoid deadlines out of politeness, others out of laziness. Whatever the reason, bosses who do not set deadlines are contributing to their employees' stress and uncertainty.
Here are a few things that happen when you do not set a deadline on an assignment.
First, the employee will either assume that it is top priority or bottom priority. For some employees, any task from the boss requires immediate attention. They will assume that the boss wants them to pause all other work to complete this. Or they will operate as if that is true, whether or not they believe it, in order to impress the boss with how quickly they can work. Other employees will assume that tasks without deadlines are lower priority than all tasks with deadlines. They will keep pushing this task to the bottom of the pile as new tasks with discrete end dates get added to their workload.
Second, you employee will spend the wrong amount of time on the task. Deadlines give employees a sense for how much work to put into an assignment. For most jobs and most people in the world, quality standards are not rigidly set. There is a spectrum to the concept of "finished work." Without a deadline, perfectionist employees may never be "finished." The boss is expecting a result that can be accomplished in about three to five hours' work, whereas the employee is pouring twenty or thirty hours over the course of a month, getting it "just right." The opposite may be true. Some employees simply do not think about work until it needs to be done. Without a deadline this task never makes it onto their radar, it does not cross the threshold into "needs to be done." They will do virtually no work on it until you follow up. Then they will slap together something that is technically finished but not nearly up to your standard.
The encompassing point is that employees will assume things that are not explicitly communicated. They will make assumptions about the relative priority of various tasks, and priority equates to time spent. Deadlines are a quick and easy shorthand for explaining the importance of any given task.
The action items of this post are about as simple as they get: always set deadlines. Instead of "Work on X," say, "Deliver X to me via email by the end of work on Tuesday." There is really nothing more to it. Provide a time and a date for every task, every single time. If you forget, catch yourself and follow up with a deadline. Just set deadlines.
There are a couple main reasons why managers avoid deadlines. The first is simply a form of laziness. The boss has not considered the details of the task they are assigning. They have not thought through the amount of work it will be or its priority relative to other tasks. We all get busy enough to do this a little bit. Poor bosses do it a lot. In the worst cases, this is a cowardly form of CYA. The boss is intentionally not providing a deadline so that they can blame their employees when their deadline is not met. This managerial laziness is morally offensive, but it happens.
Bosses avoid deadlines for another reason, which stems from politeness and unwillingness to assert their authority as a boss. These managers want to respect their employees' autonomy. They see a deadline as tantamount to saying, "I know your priorities better than you do." I have a lot of respect for this reasoning. A boss should indeed avoid leaning on their authority as often as possible. You get better results when you work from a place of relationship-building and collaboration.
However, you cannot be afraid of your managerial authority when using it is the right tool for the job. Here, avoiding the use of your authority leads to worse outcomes and also damages the relationship. Employees will feel like you are dinging them when you ask about X before the deadline arrives, even a benign question like "Are you finished with X yet?" And without a deadline, the deadline for X can never arrive.
There is a solution that both meets my advice and maintains respect for an employee's autonomy: suggest a deadline and get their signoff on it. It looks like this: "Please get started working on X and email me the results. How does a deadline of next Tuesday by the end of the day sound?" Simple, right?
When you set deadlines on tasks, you are helping your employees understand the relative priority of their work. Do it every time.