What is the "last in, first out" productivity method?

Jun 16, 2022

Table of contents:

1. How does the “last in, first out” method work?
2. What are the benefits of the “last in, first out” method?
3. What are the drawbacks of the “last in, first out” method?
4. When should you use the “last in, first out” method?
5. When should you not use the “last in, first out” method?

The “last in, first out” productivity method is a simple system for choosing the next thing to work on by what was added to the queue last. It’s a straightforward, and predictable method for organising your tasks that originates from the world of lean manufacturing.

In this post we’re going to be looking at the “last in, first out” method, its benefits, drawbacks, and when you might want to use it to organise your tasks.

How does the “last in, first out” method work?

As you can probably guess, “last in, first out” is the opposite of the “first in, first out” method we’ve looked at previously.

“Last in, first out” is where the next task to be worked on is always the newest task into the system. This has two important consequences.

Firstly, new tasks are more likely to be completed on time (or ahead of time) because they are prioritised over older tasks.

Secondly, older tasks get increasingly more overdue as new tasks enter the system.

The “last in, first out” maximises the number of tasks that are completed on or ahead of time, but sacrifices older tasks, which will likely end up very overdue.

If you’re struggling with your productivity, a good first step to improving your situation is to find a simple productivity methodology you can stick to. “Last in, first out” is potentially a good choice.

What are the benefits of the “last in, first out” method?

As with the “first in, first out” method, “last in, first out” is a very simple process with little cognitive overhead. You won’t need to make any tough decisions on what to work on next because that decision has already been made for you.

Secondly, newer tasks are more likely to be completed on, or ahead of time. Depending on the type of tasks you are working on, this might be a critical characteristic of the method you are looking to implement.

What are the drawbacks of the “last in, first out” method?

The major drawback of “last in, first out” is that older tasks are sacrificed for the benefit of newer tasks. This might not be a problem for certain types of tasks and workloads, but it’s likely going to mean that this method is ruled out for the majority of people.

All productivity methods will fail if it doesn’t align with your objectives. This is made very clear when you look at a method such as “last in, first out”, which makes its benefits and drawbacks very clear.

When should you use the “last in, first out” method?

So as you can see, there is very little reason to use “last in, first out” unless your objective specifically allows certain tasks to be very overdue in order to ensure the majority of tasks are completed on or ahead of time.

As tasks are completed in the reverse order of which they were added to the queue, another prerequisite is that the dependencies of the tasks flow in the right direction. You’re going to be stuck if you can’t complete the latest task because it depends on an older task to be completed first!

It’s probably also a good idea if all of your tasks are very similar in scope, priority, and duration. If these task characteristics vary widely between tasks, you will likely encounter problems.

In order to find success with “last in, first out” you need to be willing to sacrifice certain tasks and allow them to go very overdue. This tradeoff must be worth it to have the latest tasks be completed on time or ahead of schedule.

However, with that being said, if you’re currently thrashing trying to keep your head above water, having any method is likely going to be better than scrambling from task to task.

“Last in, first out” is a very simple productivity method that is easy to understand, follow and stick to.

When should you not use the “last in, first out” method?

There are many reasons why you would not want to use “last in, first out”.

Firstly, if your tasks are very different from each other, you will likely run into problems. For example, if specific tasks have high priority deadlines that can’t be missed under any circumstance, you run the risk of missing the deadlines using this method.

Secondly, if your tasks have very different durations or complexities, you will find that the queue can get blocked. This problem is compounded if your tasks also have very different priorities.

Thirdly, it’s going to be very difficult to use this methodology if you are required to work synchronously or collaborate with other people. Sacrificing the optionality to schedule your work is the cost of having a very simple productivity method.

And finally, “last in, first out” is also incompatible if you want to optimise your choice of what to work on for your mental state. Again, you lose this optionality when you pick a very simple method that has a rigid structure for selecting the next task.