How to Estimate a Task You Have Not Done Before

To estimate a task you have not done before, define the finished result, split the work into parts, and identify what you can base each estimate on. Use related work where it genuinely applies. For the unfamiliar part, name the missing information and decide whether a limited check would help. Keep the total conditional on those assumptions.

An estimate can be useful without being certain. If you cannot yet explain a number, identify the input or check you need before supplying it.

Define what finished includes

Write down the result in enough detail to distinguish it from a larger task. Include:

• The output: what needs to exist, in what form and with which required features.

• The starting material: what is already supplied and what condition it must be in.

• The finishing work: checks, corrections, export or handoff that belong in this task.

A missing source file and an unfamiliar step are different problems. If you do not have the recording you are meant to edit, first establish what will be supplied. If a reshoot or another language is later added, estimate that changed scope separately.

Give each part a basis

Look for a comparable piece of work you have actually completed. Check what was similar and what has changed: the source material, tools, quality required or your familiarity with the process. If an experienced person can help, give them that same scope rather than asking how long the task takes in general.

McGill’s student-learning guide to time-task estimation recommends considering assumptions and constraints, referring to related past work, separating components, and comparing estimates with actual time. The work example below applies those ideas to a small independent task; its numbers are fictional.

A worked example: one four-minute tutorial

Imagine an independent educator preparing a finished four-minute screen-recording tutorial. A script and an existing recording are supplied. The task includes trimming that recording, preparing or checking captions in one language, exporting the result and playing it back once. It excludes recording again, translation, redesign and external approval rounds.

The educator has related editing experience, but the supplied caption material needs checking. For this illustration, use these allowances in active work minutes:

• Open the supplied files and confirm the output: 10–20 minutes. Check that the recording and script are usable for the stated task. Caption-specific investigation is counted in the caption part below.

• Trim the existing recording: 30–50 minutes. This is an illustrative allowance based on related editing work.

• Prepare or check captions: 20–60 minutes. This is the main uncertain part. The allowance includes a bounded check of a representative section, plus the caption work that follows.

• Start export and inspect the finished playback: 15–25 minutes. Count active setup and checking here. Passive processing time is separate.

Add the lower assumptions: 10 + 30 + 20 + 15 = 75 minutes. Add the upper assumptions: 20 + 50 + 60 + 25 = 155 minutes.

The initial estimate is therefore 75–155 active minutes under the stated assumptions. These are sums of hypothetical component allowances, not measured editing rates, statistical confidence limits or a guarantee that the task will fall between them. The four-minute output length alone does not establish the work required.

Check the uncertainty, then revise the estimate

Choose a limited check that addresses the main unknown. In this example, the educator checks a representative caption section and finds that a compatible caption file is already supplied. Suppose that supports revising the caption allowance to 10–20 active minutes for checking the supplied captions.

That revised caption allowance includes the sample check already performed and the remaining caption work. It is not another 10–20 minutes added on top of the check. Keep the other component assumptions unchanged:

• Revised lower total: 10 + 30 + 10 + 15 = 65 minutes.

• Revised upper total: 20 + 50 + 20 + 25 = 115 minutes.

The 65–115 minutes is a revised estimate for the whole task from the start, including the investigation. It is not an estimate of the work still left after that check. Work already completed must be accounted for once when estimating what remains.

A short sample may miss harder sections. The revision assumes the remaining captions are comparable to the section checked. If later sections reveal missing or inaccurate captions, revise that part again instead of treating the first sample as proof that all captions are ready.

Keep active work separate from elapsed time

Active effort is time spent doing the work. Elapsed time also includes processing, waiting and gaps between work sessions. If an export runs while you are not working on it, that processing time can affect the finish time without adding the same amount of active effort.

The example’s totals therefore do not supply a calendar completion time. Another person’s review is outside its stated scope. If your actual task requires that review, account for both any extra work and the waiting involved.

Leave an estimate you can update

Keep a short note with the task: what the estimate includes, which related work informed it, the uncertain assumption, and what finding would change the number. For the revised example, that could be:

65–115 active minutes in total for the existing recording, one-language caption checking, export and one playback check. This includes the caption investigation already done and assumes the remaining captions are comparable. Passive export processing is additional elapsed time. Recheck the caption allowance if harder sections appear.

After completing the task, compare the actual work with the parts you estimated. Note the reason for an important difference while it is still clear, such as missing material or a repeated correction. That gives a later estimate a specific comparison rather than an unexplained multiplier.