3 Questions for Easier, Less Stressful Project Estimates
Although I disagree with the fervent #noestimates crowd about several of their arguments, they make some valid points. In an agile world where the ultimate product is not clearly defined up front and development is a discovery process, the notion of “precise estimates” is laughable.
We part ways when they assert that no estimate is better than a crude one.
If my car starts acting strangely and I take it to the shop, I expect one of two conversations:
- The service rep recognizes the problem and can tell me with 80% confidence about how long it will take and what it will cost to remedy the problem, assuming their prediction about the problem is correct and no other issues are discovered
- The service rep looks puzzled, says, “There are several things that could cause that,” and suggests a cost and time estimate—not to resolve the problem, but to diagnose it
Estimates serve a number of purposes, but one of the most important is to inform decision-makers about whether it is worth solving a problem as it is currently understood. How would you feel if the service rep said, “ I don’t know what the issue is, but give me your credit card and we’ll start diagnostics. I’ll call you if we figure out the cause!”
Developing credible estimates is hard. It asks us to make informed guesses about the product we are building, the team that is building it, and the future. These are all uncertain—for instance, I doubt any of the project managers I coach had “unexpected quarantine” on their “assumptions about the future” bingo card, but here we are.
Here’s a counterintuitive technique: Instead of asking for one estimate predicting the cost and schedule of a piece of work, ask for three. Three-point estimates are more useful and usually less stressful than their single-point alternative.
These are the three prompting questions:
- If your team performed tasks of similar size and complexity 10 times, what is the best realistic case you can imagine in terms of time and resources (e.g., things don’t go perfectly, but they go smoothly and well)?
- What is your best guess about the time and resources that would normally be required to perform this task?
- What would likely be the effort and duration of the most frustrated of your 10 attempts? What is the longest you can imagine it taking, absent some external drama?
The three-point estimate relieves the team from the pressure of trying to accurately predict the future and instead asks for a range of possibilities they think are credible, based on their experience and the best information available.
This reinforces that estimation is not an exact science. It also calls attention to tasks where the team has a great deal of uncertainty, highlighted by tasks with a large spread between the best and worst case. This method fosters a conversation about what can be done to reduce that uncertainty (prototyping, further research, more design) prior to providing information to executives.
Remember, these are estimates, not hard and fast predictions of the future. In the hands of responsible decision-makers, thoughtful estimates can do a lot to identify risks and set expectations.