We've added a few settings to Sled Team recently, that advanced users can use to tweak their forecasts:

• "Use data from the last [week to as much as two years]": this lets you change the interval of your past data that Sled Team uses to calculate forecasts.
• "I need to be [50 to 98%] confident in my forecasts": this lets you change the confidence level of your forecasts, to make them more or less conservative.

NOTE: these features are not necessary for most people, in the course of normal work. If this sounds confusing to you, or like it's another thing to keep track of, just don't worry about it for now. The default settings in Sled Team will work great for most people and teams.

With that important caveat out of the way, let's get into explaining what these are and why you might use them. First up, the interval.

Interval

The default for Sled Team is to use all your data as the basis for making forecasts, up to a maximum of two years. This is the simplest setting; it just uses basically everything you've done to forecast how things will work in the future.

But perhaps something unusual has happened for you recently! Maybe you got sick for a month and were totally unable to work. Maybe you went on a year-long round-the-world vacation. There are things that can happen in life that artifically lower how much you can get done, and you might not want to forecast your future productivity on the basis of a dry spell.

The opposite can also be true. Maybe you've spent three months working way, way too hard, a hundred hours a week, and you've gotten tons done, but you also know you can't keep this up without harming your health. Maybe you've had something to do lately that's just really, really easy, so you got a lot of things done fast, and you know that things won't stay that way.

In situations like these, you might want to adjust your interval, to exclude a weird stretch of time that you don't think is representative of "normal."

Now, the trick is that tweaking your interval can also be dangerous. If you know you had a slow week where you were really struggling, it can be tempting to exclude that to juice your numbers.

I highly recommend that you resist this temptation.

Part of the philosophy of Sled Team is that we want to be realistic about what we can accomplish, and we want to work at a sustainable pace. If you exclude the slow periods, the holidays, the vacations, the sick time, you're not going to have an accurate picture of the future. Why? Because you will also have slow periods, holidays, etc, in the future and for the rest of your life.

So, be careful with this, and don't mess with the interval unless you know it makes sense. But if it does, it's here for you to experiment with.

Confidence

One of the really hard things about building productivity software is that everybody works a little differently. When people do different kinds of work, they might work a lot differently. That makes it tricky to create something that works for all people.

Here's an example: a student in an English class has a series of essays to write, each with a deadline. He wants to know how long it usually takes him to write essays, so he can plan his time. However, he's not really running that much risk, because to some degree he can fit the work to the time available. Maybe he'd prefer to write a rough draft and then revise it at least twice. If he's running out of time, though, hemight decide to just do one revision. If he's really tired and swamped, he might YOLO and turn in the rough draft. Or perhaps he knows that his teacher will give him an extension if he needs it. For this student, he may not need to have high confidence in his forecast date.

Now, a counter-example: a freelance programmer has signed a contract to build a piece of software for a fixed amount of money, by a specific date. If it takes her longer than expected, she might have to work long hours, won't get paid for the overtime, and might even have to pay a penalty to the people who hired her. She can't afford as much risk as the student, and needs a high confidence forecast date, one that she can meet most of the time.

You might be asking yourself, why doesn't everybody just use high-confidence forecasts? What's the downside?

The issue is that to get high confidence, your dates have to be more conservative. In some cases, they need to be much more conservative. Depending on what your past data looks like, a 50% confidence date might be two weeks away, while an 85% date might be four weeks away, and a 98% date might be twelve weeks away. You may not be doing the kind of work where you need that kind of confidence, and you're more comfortable with a riskier date.

It's important to be honest with yourself about what you're okay with. Low-confidence dates look really appealing, but they can leave you in real trouble if you miss them. High-confidence dates can reduce your risk and stress, but whoever you're doing the work for might balk when they see them.

To bring this full circle, you might well want to not worry about these issues, and just leave your confidence setting at its default 85%. That level of confidence is broadly useful for a lot of different kinds of work. But if you find that doesn't fit with what you need to do, you have something you can experiment with.

Good luck, and may your confidence be grounded in facts!

—Evan