What Is Time Estimation?
Time estimations are used as a way to predict the amount of time it will take to complete a certain task or project. They can be useful in planning and managing your time effectively, especially if you have multiple tasks to complete or deadlines to meet.
How accurately you're estimating time will depend on your understanding of specific task/project requirements and your ability to complete them. The more you know about the inner workings of a particular task and/or project, the more likely it is that you’ll be to create an accurate time estimation.
As a side note, it’s important to remember that time estimates are simply estimates. They're not guarantees and may need to be adjusted as the project moves forward and new challenges arise (e.g., a co-worker gets sick, upper management decides to change directions and more.).
However, by estimating time in an informed way, you can increase your chances of meeting a specific deadline or completing all of your tasks and projects within a given time frame.
Estimating Time: Factors to Determine Task Duration
These are the most important factors you need to consider when estimating time for specific tasks:
- Task difficulty: The more complex your task is, the longer it will take you to complete it. Consider the level of difficulty, the number of steps involved in finishing it, and any other factors that can help you determine the difficulty of a specific task.
- Level of experience: If you've completed similar tasks before, you could use that information and/or experience as a reference when making a new time estimation. On the other hand, if you lack experience, you might want to include that when estimating time and give yourself enough room to learn more about the inner workings of that particular task.
- Available resources: Think about all the resources you'll need for a specific task, like equipment, software, or people. If you don't have access to the right resources, it may take you more time to complete a task, and that will affect the way you estimate time.
- Potential roadblocks/obstacles: Try to identify potential obstacles and challenges that could slow you down (e.g., technical issues, communication barriers, or unexpected delays). This will help you make contingency plans and adjust your time estimations accordingly.
- Deadline or due date: If you have a deadline to meet, make sure to take that into account when making time estimates. Be realistic and plan accordingly.
- Other commitments: Consider any other commitments you have, such as meetings, appointments, or other tasks. This will help you plan your time more effectively and avoid overcommitting yourself.
6 Steps to Improve Your Task Time Estimation
To make time estimates, you should do the following:
Step 1: Identify all the stages required to finish the task and break them down into smaller components.
Step 2: Estimate the time for each component. Consider the complexity of each component while taking into account your experience level to roughly calculate how long it will take you to complete each step. Be sure to account for any potential roadblocks. And, if you want to make this part of the estimate more accurate you could use a time-tracking app to gather data about task duration and its complexity.
Step 3: Add up the component times to get an overall estimate of how long it will take you to complete the whole thing.
Step 4: Pad the estimate. Add some extra time to your estimate to account for unexpected delays or complications. This will help you avoid feeling rushed or overwhelmed and give you a buffer in case something unexpected happens.
Step 5: Review and adjust the estimate. Ask yourself if it's realistic. If not, adjust it accordingly. Consider how you can optimize it or whether you need to re-evaluate the task components to improve your time estimation.
Step 6: Monitor your progress. As you work on a particular task, monitor your progress and adjust your time estimate if necessary. This will help you stay on track and make changes to meet deadlines or extend them if needed, not to mention that it will equip you with the knowledge you need to make a better time estimate next time.
Time Estimation Methods
There are numerous techniques and methods that can be used to accurately estimate time. Some of the most well-known are bottom-up estimation, analogous estimation, and three-point estimation:
Bottom-up Estimation
Bottom-up time estimation is a project management technique in which the duration of every individual task is estimated separately. Once they complete this step, managers can then add those estimates to calculate the approximate duration of an entire project. This method is predominantly used when the tasks are clear, defined, and can be broken down into smaller components.
Top-Down Estimation
Top-down estimation allows managers to estimate time for the project’s total duration by:
- Using historical data (from similar projects done in the past);
- Hiring an expert consultant (who has worked on similar projects in the past);
- Making an educated guess.
Top-down estimation is not known for being overly accurate. It’s mostly used as a preliminary means to estimate time and provide a company with a rough outline of how long a project could take. The main goal of this method is to give businesses a quick and easy way to evaluate if a particular project is going to be feasible and whether or not they should invest more time and resources into said project.
Analogous Estimation
The analogous time estimation method is very similar to top-down, and it’s used in project management as a means to create a rough estimate for a project’s duration. It uses historical data from similar projects done in the past to create a ball-park estimate for the duration of a current project.
The accuracy of an analogous estimation is directly correlated to the accuracy of the data used to create it. Meaning, the more precise information about past projects the company has, the more accurate this estimate will be. For example, if a company is using a time-tracking app to track task duration, the analogous estimation they make will be more realistic than if the opposite was true.
Three-Point Estimation
The Three-Point method is used to estimate time for projects or tasks. The estimation takes into account 3 different scenarios (estimates):
- Best-case scenario;
- Worst-case scenario;
- Most likely scenario.
After estimating the time for each, managers can then use one of the two formulas to calculate the final estimate (E).
The first one puts an emphasis on the most likely scenario and it goes:
E = (O + 4M +P) / 6
The other formula incorporates probability and aims to find the Standard Deviation (SD) and completely ignores the most likely scenario. It goes:
SD = (P - O) / 6
Example of a Time Estimation
Next, we’ll show you how to estimate time using the Three-Point method!
Let’s say that you’ve done a similar project to the one you’re working on now in the past, that you’ve collected the data about task duration, and that you understand the ins and outs of said project. Let’s also say that a similar project had exactly 100 tasks and that they collectively took 100 hours to complete.
With that information, we can start making the initial 3 estimates (or scenarios):
- Most likely scenario (M) = 100 tasks = 100 work hours; (this scenario assumes that nothing is going to be different from the last project);
- Best case scenario (O) = 100 tasks = 70 work hours; (this scenario assumes that because you’ve done a similar project before, you’ll be able to do this one faster);
- Worst case scenario (P) = 100 tasks = 110 work hours (this scenario assumes that everything that things can go wrong and accounts for scope creep);
Now that we have the initial estimates, we can add those numbers to a formula and make the final estimate.
E = (O + 4M +P) / 6
E = (70h + 4 x 100h + 140h) / 6
E = 610h / 6 = 101,6h
And there you have it, your final time estimation predicts that you will have to put in 101,6 work hours to complete the new project.
Why Is Estimating Time Important?
