Tough question. How do you even estimate the size of a dog? Now imagine we put numbers on the different dog breeds, and we agree together that the Chihuahua is 1 Dog Point, the Border Collie is 5 Dog Points, and the St. Bernard is 13 Dog Points. We also decide to use the following Fibonacci-like sequence to estimate dog sizes: 1, 2, 3, 5, 8, 13, 20, 40, I would be able to throw any dog at you and assuming you are familiar with the dog breed, you would be able to estimate it with Dog Points.
Even though you would have no clue whatsoever about the exact dimensions of that dog. You now have mastered the secret art of Dog Point estimation. I hear you say, why should I care about that exactly? Good question! Story Points basically function the same way as Dog Points. In the end, Story Points represent an unknown amount of time. All we know is that Backlog Items with the same Story Point estimate take a comparable, but unknown, amount of time to complete.
So how do you Story Point Backlog Items? Some of you may have heard that Story Points are about uncertainty, complexity, or risk. Uncertainty, complexity, and risk are all factors that influence effort, but each of them alone is not enough to determine effort. Some teams even go further and do not use Story Points at all. This is called NoEstimates. I love writing; it's a path to a world where everything goes, really.
I also create and manage content for Jexo, with the hope of adding value to an industry PPM that is essentially about people. Listen to this article on Spotify The basics of using story points So what is a story point anyway? How are story points decided upon?
Why would developers use story points? How to estimate story points The 3 Components in Story Point Estimation Story point estimation is based on three main components: Risk includes demands that are vague, dependendencies and random changes. Complexity is related to how difficult a feature is to develop for example. Repetition is determined by how well the team member knows a feature and how monotonous the tasks are.
Why Fibonacci and not a linear scale? The Fibonacci Sequence and its Golden Ratio Phi The Fibonacci sequence is a series of numbers with each number being the sum of the two previous numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21 and so on.
Step 2 — Create a story point estimation matrix Story Point Estimation Matrix Your baseline is hereby included in the matrix as 1; this represents the story that has the least amount of risk, complexity, and repetition. Step 3 — Play planning poker to decide on story points Planning poker is a great way to have the team agree on the correct story point approximation for every item in the backlog.
Prioritization Planning Poker on the way During the sprint planning meeting, each developer receives a set of cards depicting the Fibonacci sequence. The backlog item is then brought to the table to be discussed and clarified. Each developer and tester privately gets to select the card they feel reflects best their estimation for that item. The estimators reveal their cards at the same time and once consensus is reached amongst the whole team, then we move on to the next backlog item.
How many chickens should I give you for a cow? Our modern economy could not have existed if we were stuck with such barter trading.
Then money was invented. It created an alternative to bartering and eventually replaced it. Money simplified — and expanded the possibilities of — trade by distilling all the considerations that go into determining something's worth into one number. Story points are a unit of measurement, just like time and money.
Time measures duration, money measures value, and story points measure the estimated size of a piece of work, where size is the sum of multiple factors. The concept of story points was originally developed by Ron Jeffries as part of the Extreme Programming XP agile framework.
But they have since come to be used by teams that use other frameworks, like Scrum. Teams may use story points during their backlog refinement or agile estimation meetings to give a clearer idea of how much work they can expect to achieve in each sprint. Teams estimate a task's size by taking into account all the factors that could impact completion:.
Trying to compress so many factors into one estimate might sound impossible. But with a bit of practice, it's as simple as figuring out if the flat white at your local coffee shop is fairly priced. You accomplish that feat in a split second when you see the amount, mainly because you subconsciously compare that price to a whole range of factors.
Some are obvious, like the pricing, quality, and your experience at other coffee shops. But there are also indirect factors like whether your current salary or the economic outlook justifies spending money on a fancy coffee. It's similar with story points. Estimating them will quickly become intuitive and make your task estimation faster and more accurate than time-based estimation.
Time is an outdated unit of measurement for estimating modern work because it's one-dimensional and absolute. It can't reflect all the unpredictable factors that impact the completion of tasks in complex projects, nor can it adapt to local conditions as story points can.
What's more, cognitive biases mean we're apt to over-estimate how quickly we can achieve tasks. Once your team fully understands story points, they lead to faster and more accurate estimates of your tasks than when using time.
That's because story points are relative, account for the unpredictable factors listed earlier, and are applied at the team level instead of the individual level.
The value of story points is rooted in the experiences of the team. One hour represents the same amount of time worldwide, but story points are more like money. Most countries have their own currency primarily for use within their own borders. You can then do the work of estimating story points in a meeting like Backlog Refinement , Planning Poker , or Sprint Planning. Sharing this article before your first Poker Estimation session might be a good start.
Take the absolute smallest task you'll ever need to estimate during your planning process and rate it as one story point.
This item becomes your baseline task to which you calibrate subsequent ones. Over time, you can set other guides based on previous tasks. The hardest part is getting started without prior data to rely on. Pick a different sized item from your Backlog and estimate its size in story points compared to your baseline task. Continue running through your Backlog in this way, comparing items to each other until you've assessed all their sizes.
You can do this with an estimation method such as affinity estimation or relative mass evaluation. Wondering how to estimate tasks as a team?
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