Why this is a problem!
It’s a problem because if you do it often enough you will have started several tasks and finished none which will eventually lead to a feeling of overwhelm as deadlines for the unfinished tasks loom.
It’s also a problem because what you are choosing to do may not be the most important thing requiring your attention. Therefore it does not represent the best use of your time. Things that grab your attention tend to be urgent but not necessarily important.
You can attend to the latest crisis such as the copier that’s broken down (again), a phone that rings and no one answers (but you), a rep calls and for some reason your life will not be complete unless you see him or her.
Another reason it’s a problem is because generally working on related tasks is far more productive than working on non related ones. An example would be if you put aside an hour to do nothing but correspondence you would get more letters or emails done than if you wrote a single letter or email every two hours.
Can you imagine what would happen if sports people practiced like that? Hit a ball then go to the gym for an hour then hit another ball then etc, etc. It just would not work. Similar or the same tasks can always be done faster and more efficiently when grouped. And you learn to do them better and increase your skill level at the same time.
How you avoid it.
Plan your work then work your plan it’s that simple. Ideally you will have a plan for each calendar month. However, you must have a weekly plan as a minimum. The week’s tasks are then allocated to week days.
Make sure the last thing you do today is to plan for tomorrow. Look at what your priorities are, identify your musts and should’s. Musts are important to you - should’s are important to someone else.
When you have identified your highest value tasks for tomorrow list them in order of priority, give each a time allocation and then see if when the tasks are added up they fit into how many hours per day you work. Do not allocate all your time in any given day as this never works.
Use one of the three hours at the end of the day and apart from planning tomorrow check on what was completed today. Was your time allocation accurate if not why? Record this as useful data for the future so you have your own outputs file. Get into the habit of doing this and see the results.