Sunday, July 13, 2014

Cooking an elephant carpaccio

Disclaimer: No elephants or other animals were harmed during the writing of this post.

Make me an elephant

What if I asked you to make me an elephant? Can you tell me how long would it take you? Can you guarantee that under this time estimation you gave me you will be able to create a great elephant, with all the capabilities and characteristics an elephant possesses?

Image taken from here

Tackle this huge story

Ok, so us, software engineers, are not that good at creating elephants. We'll leave this to the lady elephants to cook new elephants. But we aim to be good at creating software.
Tackling a large story may be very puzzling. Both from our (developers) perspective and from the product manager's eyes.

How many times have you started working on such an enormous story and found out that there were a lot of holes in your complete mega-design? How many times have you been mistaken in your estimations? How many times have you found out that large portion of your code is not in use or not what the customer/product described?

It's hard for us to plan every little detail in the system ahead. There are a lot of unknowns down the road, which will be careless of us to presume we know, and will make it difficult for us to give an honest estimation. Also it's not easy for the product as well to define every little detail given all these unknowns.

Elephant carpaccio

Elephant carpaccio is a technique that helps us tackle such a big problem. Instead of trying to create an entire elephant, we can try breaking the manufacturing process to small stories. Each such story must stand on its own - meaning, provide some (some == more than 0) value to our users and be independently testable (meaning - no need to wait for other parts of the story to end in order to test it).

In an elephant carpaccio we'll try to follow a simple pattern:
  1. Create a very thin flow
  2. Thicken this flow by each time adding another layer or sub-feature to it.

Creating the initial flow

In order to find this main flow we better ask ourselves what is the main problem we try to solve. We can then map the main use-case. The one that solves a large portion of the problem. Then we can decide this will be the flow.

It's important to understand that this is ok to state that this flow will not stand on its own for releasing to the market. If we would to design an ATM, our main flow would probably be - withdraw money. But we can't send it to production without making sure the flow is transactional, secured, audited in the bank's books and so on. But creating the really basic flow of withdrawing money, in a very naive way (maybe even without checking if the customer has sufficient funds in his account) will already give an enormous value and a great starting point.

Thickening the flow

After we understand the initial flow we're in a much better position to split the story. In this point we need to ask ourselves some questions to understand the more smaller details by which we can split the story. I'll give example on how we do it in my next post.

Focus, Build, Increase Trust

Sometimes in the work of engineers with product we encounter a lot of trust issues (if you speak Hebrew, take 5 minutes to hear from a former colleague of mine about this in this ignite talk or read her blog-post, in English, instead). Product managers often feel they do not exactly understand where the engineering are in the process and whether things go as they wanted. The engineers are not always aligned with the vision the product managers lead to. It sometimes makes them scatter to the less important areas of the feature, the ones that are a nice-to-have (for example - having an ultra beautiful button is important in an ATM, but less important than having the functionality to withdraw money).

By working with small portions we allow product to define the priorities of the work by having the engineering focused and aligned with what's really important. The engineers, when the carpaccio is done right, know exactly what they should do now. They're (usually) not distracted because they work in a very small units of work. It also allows product to change requirements on the way because the engineering process starts with the certainties and the most important things. We can change the rest of the plan as we continue to progress.
When combining such story-splitting techniques with other agile methodologies like sprints, dailies and so on, we can create a better communication between product and engineering, improve trust and improve the productivity of the team as a whole.

My Rules of Thumb for Carppacioing

  1. Split an epic to stories in such a way that each story would provide value. Any value.
    How you define value you ask? Value is defined as something that you can show to a user and (s)he would actually care and be able to give you feedback about it. 
    (A new button that doesn't do anything yet is value; A new table in the DB is not).
  2. Repeat bullet #1 for each story you created and try to split it some more until you're absolutely certain you can't or that further splitting would just increase the overhead of implementing it too much.
  3. In your sprint planning split each story to very short tasks. These tasks do not need to provide user value. They can and should be very small but not too small (less than 0.5 day is probably too small) in order to not increase overhead.

For those of you who would like to deepen your understanding on the subject I would suggest  Lars Thorup's presentation on the subject which I found very interesting and concise.
Also, in my next post I'll give a more detailed example of the carpaccio method. Stay tuned...

Find me on Twitter: @AviEtzioni

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