Category Archives: BDD/ATDD

How the industry broke the Connextra Template

Apples, Oranges and User Stories

Read this on medium.com via ideas.riverglide.com.

Imagine you’d never seen an orange or an apple before. Then, imagine you read a few articles showing an image of a shiny, red fruit, saying – “This is an orange, it will help you with your vitamin C deficiency”. It’s a similar shape to the foods you’ve eaten for other vitamin deficiencies so still fits your model. You proceed to eat lots of this red, shiny, crunchy, refreshing fruit and you teach your colleagues the same. Now they’re eating “oranges”…

“You keep using that word, I do not think it means what you think it means.”

After some time, your vitamin C deficiency still hasn’t improved. So everyone says “down with oranges, they don’t work”—including the some of the authors who’s articles you’d read. The problem was that you were eating apples, not oranges. But it’s too late, you, your colleagues, some authors of the articles you read—now have a disdain for anything labelled ‘oranges’.

This sounds ridiculous, but only because you know the difference between oranges and apples. Yet, it reflects the same kind of wide-spread misconception that has fuelled the growing disdain I’ve seen towards the Connextra Template—As a…I want to…So that…

Summary (TL;DR):

  • Some believe User Stories are analogous to product features & that they should state business benefit – this is a fundamental misunderstanding;
  • User Stories are about what the user will be able to do/achieve (not actions or features they’ll do it with);
  • The Connextra template (As a / I want to / So that) helps us start valuable conversations about: who the user is, what they want to do and why;
  • Some tried to ‘improve’ the Connextra template to capture features and business benefit (software requirements). These ‘improvements’ spread far and wide, propagating the ‘feature’ misconception of user stories;
  • It’s not too late to make the paradigm shift away from writing ‘software requirements’ to truly understand user stories as ‘the story the user wants to be able to tell’;
  • Truly understand the User Story paradigm and you realise that the Connextra template is as useful as ever.

The root of the misconceptions

Think of a User Story as a short-story that a user will be able to tell about what they want to do and why they want to do it. It’s not the feature the product will have or the actions they’ll perform, it’s what the user will be able to do – as in achieve. One story may actually mean subtle or significant changes to multiple features, involving several actions.

“Stories aren’t a different way to write requirements, they’re a different way to work”  -Jeff Patton

User stories are a paradigm shift, a different way of working. Jeff Patton explains this superbly in slides 1-50 of his User Story Mapping slides (I highly recommend you flip through them). Jeff highlights that “Stories aren’t a different way to write requirements, they’re a different way to work”.

 
The misunderstanding that User Stories are just a different way to write old-style software requirements has contributed to continuous deterioration in how the Connextra template is communicated across the industry—changing User Stories into product features (or user action within a feature). Product features and actions within them generally describe the product (not the problem)… again, like old-school requirements.

“A further problem with requirements lists is that the items on the lists describe the behavior of the software, not the behavior or goals of the user” –Mike Cohn, User Stories Applied (2004) Addison Wesley

Unfortunately, the problem wasn’t with the Connextra template, it was with widespread misinterpretation of it. This misinterpretation propagated so far and wide, that many teams now experience the problems caused by slicing work into product features (problems that User Stories are designed to solve). And now people are saying—“User Stories are broken!” and “the Connextra Story Template doesn’t work”. Clearly, comparing apples and oranges, much like in the opening story.

How did this happen?

The Connextra template highlights the who, the what and the why from the user’s perspective:

As a <someone>
I want to <do something>
So that <some result or benefit>

This helps us start the right conversation; exploring the short story a user could tell about something they’ll be able to do – hence the term ‘User Story’. The “As a…” helps us start empathising with the user. The “I want to…” gets us thinking about what they want to do (not how). The “So that…” get us closer to their motivation – why they’d want to do this.

Unfortunately, many people mistook User Stories to be just a different way to write requirements—which they’d always expressed as features & functionality. In their efforts to help colleagues and peers understand user stories in the same way, several people began sharing this template:

As a [role]
I want [feature]
So that [benefit]

Many teams found that whole features were too big to implement in a short enough window, so we also saw a variation on this where the interactions within the feature were described:

As a [role]
I want to [action]
So that [outcome]

Others sticking with the larger feature model, asked about ‘benefit’ part – what’s that for? Is it the benefit to the user? If it’s about the user, then where do we ‘document’ the business benefit? The question of ‘value’ and ‘business benefit’ was seen to be missing so we started to see:

As a [role]
I want [feature]
So that [business benefit]

People didn’t always know what the specific business benefit of a feature was so they started writing “As a… I want ” and left the “So that…” part out. So, a different format was put forward to encourage thinking about the business benefit and we ended up with a catch-all for feature or action—“functionality”—plus the business benefit as the opener (which became a confusion between what the business wanted and what the user wanted):

In order to <achieve some value>
as a <type of user>
I want <some functionality>

Whether it was the intent or not, I believe that these variations made it easier for teams to think they were working with User Stories when in fact they were simply capturing product-features and business-benefits like old-style software “requirements” – only dressed in a User Story like template.

The opportunity

User stories are about the user – hence the name. It’s a way of working, not a way of writing requirements. This is an area we all need to get better at explaining.

What we write on the User Story card (or electronic equivalent) using the original Connextra template helps us start the right conversation about users’ needs, slicing by value to the user. Starting the right conversation to slice by business value is a different problem.

The original Connextra template works just fine for User Stories that tell a story about the user. The template wasn’t trying to fix the mindset of slicing-by-feature. Books like User Stories Applied were there for that. The misconceptions began when people assimilated User Stories through their feature-biased filters and tried to ‘fix’ it – rather than question their own understanding.

This left many teams with “features dressed as stories” caused by a fundamental, yet common, misunderstanding. Who knows, I may have once shared in that misunderstanding myself. Now, we have an opportunity to change this by learning more truths about User Stories so that we can all benefit from increased agility.

Have you been working with features dressed as stories? If so, and you want that to change, here’s a place to start.

 

Remote Coaching & Pairing: for Individuals & Teams

If you’ve worked with me or Andy Palmer before or you’ve read one of our blog articles, sometimes you might be thinking…

Antony/Andy would know how to make what I’m doing better/easier right now, if only they were here!

Maybe all you really need is 30 minutes to an hour pairing or just talking, not a whole day of our time. Maybe all you need is a few emails back and forth between us. Rest assured, we’re here and we’re happy to help, on anything including:

  • For product and technology teams:
    • Thinner slicing of your Minimal Viable Products (MVP)
    • Effective user stories, Feature Injection & agile business analysis
    • Effective Cucumber scenarios
    • Communicative, narrative code
  • For coaches, managers and leaders:
    • Values & building a culture of innovation
    • Enabling more adaptive teams
    • Challenges of culture and process change
    • Facilitating effective workshops: story-sizing/planning/retrospectives

All sessions are strictly confidential and we’re more than happy to sign a mutual non-disclosure agreement if required. If you aren’t sure if either of us can help, why not get in touch and let’s see. If we can’t, it won’t cost you anything…

Individuals: Pay what you think it was worth

Maybe you need to talk about a challenge you’re facing with your team, colleague or management. Perhaps you have some nightmarish Cucumber scenarios that are making your head hurt. Perhaps you just need someone independent to bounce ideas off.

We’ll have a conversation on Skype, Google Hangouts, Facetime or just on the phone. At the end of the time, all you do is:

  • Tell us what you thought it was worth and
  • Pay only what you are comfortable paying

Money is relative to both your personal income and your responsibilities. You know what they are and we trust you to make a fair exchange of value. All we ask, when you pay whatever amount you’re comfortable with, is to tell us what you thought the session was worth.

You may work in a company that trusts & values your judgement, allowing you to expense personal development activities. This model equally applies, but when that isn’t an option…

Companies: Pay what you think it will be worth

Many large, established companies find it hard to work in the above way. You may not feel you have the freedom to work in the above way (in which case we really should talk). Your manager may want to sign it off and your finance team may want to have a purchase order in place for a fixed amount before you talk to us. So, if you want let’s talk a bit about the challenge and what a new way forward in addressing that challenge is worth. We’ll agree a price and we’ll go from there.

After a chat, you might find that you have a lot more freedom than you think and we can help you make things easier. For more information, get in touch with an email or a call to +44 845 056 9606. We’re happy to help.

It starts with a story…

If agility to you means maximising the opportunity of realising value early & often while rapidly adapting and responding to market feedback then user stories, applied effectively, can facilitate that. However, one common misunderstanding of user stories seems to hinder teams from achieving the benefits they hope for…

A user story is a “short descriptions of functionality–told from the perspective of a user–that are valuable to either a user of the software or the customer of the software”[1]. You may first encounter stories in this form:

As a microblogger,
I want to find out as soon as others mention me,
So that I can choose to respond while topics are current.

One common misunderstanding of user stories might result in the above example looking more like this…

As a microblogger,
I want a notifications screen showing my mentions,
So that I can find out as soon as others interact with me.

The problem here is thinking of user stories in terms of what the user will have, rather than what they’ll be able to do. This can cause avoidable dependencies that limit your flexibility, reduce your speed to market and limit your ability to change direction based on market feedback.

These dependencies can be dramatically reduced if our user stories steer the conversation towards what the user will be able to do. Let’s explore why…

What the user will have (features)…
Let’s imagine we envision a house (which will be made of lego in this exercise). What stories would you write for your lego house? Here are some of the typical stories people write:

  • As a cook,
    I want a kitchen,
    so that I can prepare food.
  • As a parent,
    I want a master bedroom,
    so that I can sleep comfortably with my partner.
  • As a car-owner,
    I want a garage,
    so that I can park my car off the street.

Have a think about what’s involved in delivering these stories with a lego house, building our final vision of the kitchen, the bedroom, the garage. If our vision is to have the master bedroom on the top floor, then we can’t have a place to sleep until we’ve built the ground floor. To build our garage ‘iteratively’ we will focus on building the walls first, then put the roof on. Essentially, the architecture drives the order of implementation, not what is of greatest value to us.

The problem here is that these stories are encouraging us to fixate on specific solutions to each problem. Ideally, we want the story to be about what the user will be able to do (i.e. sleep comfortably together), not what they’ll have (a bedroom).

In these examples, as is often the case, the problem we’re trying to solve is there, just in the ‘so that’ part. Getting everyone to share in an understanding of the problem(s) we want solved helps us prioritise based on business value…

What the user will be able to do (capabilities)…
Now, imagine if we had stories like this:

  • As a cook,
    I want to prepare hot food for the family,
    so that we can safely enjoy various fresh foods.
  • As a parent,
    I want to sleep comfortably with my partner,
    so that we can keep each other warm.
  • As a car-owner,
    I want to park somewhere safe,
    so that I can keep my insurance premiums low.

Have a think about the different ways we could initially solve these problems (from camping cookers, a mattress on the floor and a driveway to park the car). We can meet all of these needs rapidly without having to achieve the final vision but make it possible to layer on more and more refinement to each one evolving to the solution and enabling us to discover the solution we really need.

when what we want is “a thing” then what we are describing is not a user story – it is a feature.

Features (“I want a…”) vs. Capabilities (“I want to…”) 

Relatively recently, while running my user stories course (with Lego) to delegates at a well known company, one delegate pointed out a difference between the ‘template’ for the two story styles above. They observed that in the case of stories that are really “Features” the format tended to be “I want a…” whereas for stories that were “Capabilities” the format tended to be “I want to…”. Some found ways around this by saying “I want to have a…”.

Interestingly, the original ‘Conextra Template‘ indeed followed “I want to…” and all of Mike Cohn’s examples in his book “User Stories Applied” are indeed capabilities (although sometimes in his explanations he does refer to stories as describing a feature, his examples are generally capabilities).

In short, when what we want is “a thing” then what we are describing is not a user story – it is a feature.

(This short section was added on: 22nd May 2015)

 

A house made of lego

Flexibility & Adaptability…

Each of these stories may be broken down even further. Let’s look at the garage and all the needs a garage might meet

  • As a car-owner,
    I want to park my car off the street,
    so that I can reduce my insurance premiums
  • As a car-owner,
    I want to shelter my car from the rain,
    so that I don’t have to wash it as often.
  • As a car-owner,
    I want to hide my car from onlookers,
    so that opportunists don’t think of stealing or vandalising it.
  • As a car-owner,
    I want to hinder thieves from driving my car away,
    so that I get the lowest insurance premiums.
  • As a car-owner,
    I want to securely store my tools near the car,
    so that it’s easier to do basic maintenance.
  • …and so on.

Now think of the different ways we could meet those needs with our lego house?

Most of these stories are largely independent of each other and can be delivered in almost any order. This allows us to prioritise the stories based on value rather than the architecture of the final vision.

We’ll realise our first piece of value very quickly and continuously gain more and more value until eventually we’ll have a whole garage (if that’s what we really need). If this was something that makes us money, it would mean we’d be generating revenue sooner. Revenue would grow continuously as we continuously grow our product.

It also means we can change direction at any time, for example if we were to start getting feedback taking the garage more in the direction of a workshop with space for a car rather than just a simple garage.

In the real world
I recently helped a client interview people who had from three to five years “experience” with user stories. During the interview I pulled out some index cards and pens. I described a simple product (which was surprisingly similar to early incarnations of Twitter) and invited them to help us write some user stories for our backlog.

What each of them wrote was, essentially, a functional specification, split like use-cases into several cards, except using the above “As a… I want… So that…” template. They explained each story in terms of the screens in the user-journey such as Registration, Login, View Profile, Follow Other Users, Post a Status Update, View Status-Updates and so on. The real issue here isn’t in the name of the story, it’s in what the stories represented in their minds…

I asked them to help us prioritise them based on value. “Registration is most valuable because without it we can’t do anything else”–one interviewee explained. This means that it would not be possible to obtain any feedback about the main value proposition of the product until a number of user stories are complete. Each candidate explained the stories as dependent steps in a journey that, essentially, had to be built in the same sequence as the journey [4].

The main value proposition is sharing updates with people and seeing what others are saying. A simple screen-name (like in a chat room) will do  initially. Registration and login are largely about hindering others from pretending to be me. Could there be simpler ways of achieving this at first?

Like I said, I’m not suggesting that any of the story titles that each candidate came up with are invalid, just that they thought of them in terms of the expected solution (what the user will have), not understanding the real problem (what valuable thing the user will be able to do).

In Closing…
With tractable mediums like lego or code (with the right engineering practices around it), we are able to evolve our product to meet each user-need in turn.  This is facilitated by thinking of our user stories in terms of the outcome (e.g. shelter from the rain) rather than one possible output (e.g. a roof and four pillars). Ultimately, this way of thinking is one of the key upstream enablers to realising value early & often and brings more opportunity to rapidly adapt to feedback by dramatically reducing dependencies.
——————————-
Experience this for yourself: If you would like me to run this as a hands-on workshop with your team(s), let me know. We’ll explore how user stories work in practice, not only by writing the stories, but understanding the conversation and means of confirmation [3] that complete the practice of user-stories. I can also wrap this in a simulation of Scrum and/or Kanban so that teams can experience how user stories work in practice. I make it accessible to all team members using lego as a metaphor for software, demonstrating the principles described above. We then explore how to apply this to your products, writing some stories or reviewing and refining your existing stories to take what we learn into the real world.

Acknowledgements:
The Lego House exercise that I run has been created by combining my experience with a number of other exercises, including the “XP Lego Game” and Rachel Davies‘ Household Stories exercise.

Footnotes:

[1] “Advantages of User Stories for Requirements” by Mike Cohn (See also his book, “User Stories Applied”)
[2] Typical user story format: http://guide.agilealliance.org/guide/rolefeature.html
[3] There is a lot more to user stories than this three line statement. The simplest explanation is that this is just the ‘Card’ in the three C’s of User Stories: http://guide.agilealliance.org/guide/threecs.html
[4] A key characteristic of user stories is there are few dependencies, if any, between them and each is valuable. This is explained by the mnemonic INVESThttp://guide.agilealliance.org/guide/invest.html

Segue Steps

Sometimes customer scenarios using Gherkin (Cucumber, SpecFlow etc.) can be harder to read than necessary. Once there’s more than one “And” line in a row, I find that there’s more clutter than I’d like and it doesn’t flow as well when I read it. Let’s take this example scenario of upgrading a fremium service.

Scenario: Upgrade my SomeService subscription from Basic to Pro.
Given I am on the Basic plan
When I upgrade to the Pro plan
Then I see a message confirming the upgrade
And I see that I am now on the Pro plan
And I receive a personal thank you by email
And SomeService keeps a record of when the upgrade happened
And SomeService keeps a record of payment

There’s a feature I rarely see used, the ability to use bullets (with asterisks ‘*’). I’ve found that using this among steps with Given/When/Then can remove some of the clutter, making the scenario easier on the eye…

Scenario: Upgrade my SomeService subscription from Basic to Pro.
Given I am on the Basic plan
When I upgrade to the Pro plan
Then I see a message confirming the upgrade, and:
* I see that I am now on the Pro plan
* I receive a personal thank you by email
* SomeService keeps a record of when the upgrade happened
* SomeService keeps a record of payment

What I don’t like about this, however, is how the ‘Then’ step appears in a different context to the bullets and seems less important. To make sure that all the steps are seen as equally important, I can do this:

Scenario: Upgrade my SomeService subscription from Basic to Pro.
Given I am on the Basic plan
When I upgrade to the Pro plan
Then the following occurs:
* I see a message confirming the upgrade
* I see that I am now on the Pro plan
* I receive a personal thank you by email
* SomeService keeps a record of when the upgrade happened
* SomeService keeps a record of payment

Note how I’ve put in a “Then” step that segues from the “When” to the actual expectations.
A ‘Segue Step’ doesn’t have to do anything, other than transition the reader from the previous steps to a list of expectations:

Then /^the following occurs:$/ do #nothing
#just segue to the next step
end

Another way of using a Segue Step could be like this:

Then I should:
* See a message confirming the upgrade
* See that I am now on the Pro plan
* Receive a personal thank you by email
And SomeService should:
* Keep a record of when the upgrade happened
* Keep a record of payment

Asterisks can replace the opening keyword of any type of step, but using them in this way for Given or When steps could be a scenario-smell, suggesting that the scenario has too much detail or those steps are at the wrong level of abstraction. Using asterisks and Segue Steps are most appropriate in “Then” statements with two or more “And” lines.

After doing this, reading scenarios without asterisks and ‘Segue Steps’ now feels like the “And Then” scene from “Dude, Where’s my Car”…And then? I hope you find it useful to write better scenarios too… And then? And then? And theeeeeeeeeeeeen! And thenandthenandthen!

 

Special thanks to Andy Palmer for reviewing this blog post and helping me say it with fewer words.

Old Favourite: Radio by Example

This first appeared on my old blog in  “2008 under the title Specification by Example”. I’ve made a couple of minor refinements to the text and I’ve added the image below from the 2009 “GOOS” book .

Internet radio‘ has come a long way since it first began. Long gone are the days where you have to seek out an online station that streamed a preselected playlist with mostly music that you like, or several stations for those with more eclectic taste. Instead, services like Pandora.com and Last.fm create a personalised radio station that matches the user’s own personal taste.

These personalised internet-radio stations are far more sophisticated than just specifying what genres and styles you like. When they first started you didn’t do that at all. When last.fm first started you provided an example of a song that you like. Software analysed the song finding common aspects of the music’s ‘DNA’ – including genre, tempo, how melodic it is and countless other sound characteristics in their database. From this they create a user-specific internet radio station that matches the users taste. As you listen, you give them feedback saying which songs you love and which ones you hate. Your future play-lists are refined with each piece of feedback you provide. This feedback is in itself more examples of songs that do and don’t match your taste. As a result you’d find yourself listening to songs you’d not have otherwise discovered.

That is Specification by Example! The product (in the above, your personal playlist) evolves by inferring the desired rules and characteristics from concrete examples.

And, as several have been saying for years… Test Driven Development is just that – Specification by Example – applied to software development. Instead of examples of songs, we provide examples of what we’d like the product, or part thereof, to do. These examples take the form of tests. It so happens that the evolution of the software product is performed by humans, unlike the internet playlist evolved by a machine.

Write a failing acceptance test, then cycle over writing a failing unit test, making that pass, and refactor repeating until the acceptance test passes.

Software Pottery

“Building software” is a phrase I hear used time and again. Indeed, many do still think of software development as akin to construction.  Modern (agile) software development doesn’t feel like that to me. There was a time, like the construction architect, when we had to increment and iterate on paper and in models. The cost of computing was too high to do such iteration inside the machine. The cost difference between making a small change in our understanding and reflecting that in the actual product was too great. The cost of change meant that we had to treat the creation of software like constructing buildings or bridges. But those times are, or should be, in the past.

To me, modern (agile) software development feels more like pottery. But, instead of ‘throwing clay’ we throw our consciousness, in the form of electrons flowing over silicon, onto a spinning wheel of user-story implementation cycles.

Picture of a pot being created and evolved on a pottery wheel.
Source: http://www.flickr.com/photos/kellinahandbasket/2183799236

We evolve our understanding of what our customer wants with each conversation. We reflect that understanding by evolving the product’s shape as we touch the outer surface with each new automated acceptance test (or example scenario). We evolve its structure as we touch the inner surface with each new unit test (or unit specification). We keep it supple as we moisten it with each refactoring. Our customer looks on, gives us feedback and we start the next revolution of the software development wheel. Never letting the product dry and harden; keeping it flexible, malleable, soft(ware).

There is nothing that feels like construction here. I never feel like I’m “building” something. Much more like I’m evolving my understanding, evolving the product, evolving my understanding again and so on.

For these reasons l am not comfortable with referring to this process as “building”. I’m also not comfortable calling it “throwing” (as in pottery).

I am very comfortable calling it “development”. I use the word “develop” in terms of its literal meaning:

to bring into being or activity; generate; evolve.
dictionary.com

From the first thought of a new idea, through each conversation along the way, to each revolution of the software development wheel, I develop products.

I don’t “build”.

I create. I make. I shape. I evolve.

—————————
Footnote: I’m not aware of anyone drawing this analogy before. If you have heard or read someone explain it in this way before now, please let me know.

GhostDriver – Headless Selenium RemoteWebDriver

GhostDriver is a Selenium server that can be connected to via a RemoteWebDriver.

It runs completely heedlessly on PhantomJS but still behaves (mostly) like a typical webkit browser. By avoiding the overhead of actually rendering the page in a GUI it can run standard Selenium tests noticeably faster and on a headless build server too.

This is especially beneficial if you want to use continuous testing IDE plugins like Infinitest or JUnitMax or simply to encourage developers to run end-to-end tests more frequently.

GhostDriver is written on top of PhantomJS, a headless WebKit browser which uses QtWebKit.

It’s already 35%-50% faster than ChromeDriver despite the fact that QtWebKit has the standard WebKit Javascript engine. QtWebKit is moving to the V8 JS engine (as used in Chrome) which means it’s only going to get faster…

It’s still work in progress and hasn’t implemented the entire Selenium wire protocol yet but it’s certainly one to watch.

Presentation at SeleniumConf 2012: http://www.youtube.com/watch?v=wqxkKIC2HDY

Find it on GitHub: https://github.com/detro/ghostdriver/

Implemented by: Ivan De Marino

Scenario-Oriented vs. Rules-Oriented Acceptance Criteria

Acceptance Criteria, Scenarios, Acceptance Tests are, in my experience, often a source of confusion.

Such confusion results in questions like the one asked of Rachel Davies recently, i.e. “When to write story tests” (sometimes also known as “Acceptance Tests” or in BDD parlance “Scenarios”).

In her answer, Rachel highlighted that:

…acceptance criteria and example scenarios are a bit like the chicken and the egg – it’s not always clear which comes first so iterate!”

In that article, Rachel distinguishes between acceptance criteria and example scenarios by reference to Liz Keogh’s blog post on the subject of “Acceptance Criteria vs. Scenarios”:

where she explains that acceptance criteria are general rules covering system behaviour from which executable examples (Scenarios) can be derived

Seeing the acceptance criteria as rules and the scenarios as something else, is one way of looking at it. There’s another way too…

Instead of Acceptance Criteria that are rules and Acceptance Tests that are scenarios… I often find it useful to arrive at Acceptance Criteria that are scenarios, of which the Acceptance Tests are just a more detailed expression.

I.e. Scenario-Oriented Acceptance Criteria.

Expressing the Intent of the Story

Many teams I encounter, especially newer ones, place higher importance on the things we label “acceptance criteria” than on the things we label “acceptance tests” or “scenarios”.

By this I mean that, such a team might ultimately determine whether the intent of the story was fulfilled by evaluating the product against these rules-oriented criteria. Worse still, I’ve observed some teams also have:

  • Overheads of checking that these rule-based criteria are fulfilled as well as the scenario-oriented acceptance tests
  • Teams working in silos where BAs take sole responsibility of criteria and testers take sole responsibility for scenarios
  • A desire to have traceability from the acceptance tests back to the acceptance criteria
  • Rules expressed as rules in two places – the criteria and the code
  • Criteria treated as the specification, rather than using specification by example

If we take the approach of not distinguishing between acceptance criteria and acceptance tests (i.e. see the acceptance tests as the acceptance criteria) then we can encourage teams away from these kinds of problems.

I’m not saying it solves the problem – it’s just easier, in my experience, to move the team towards collaboratively arriving at a shared understanding of the intent of the story this way.

To do this, we need to iteratively evolve our acceptance criteria from rules-oriented to scenario-oriented criteria.

Acceptance Criteria: from rules-oriented to scenario-oriented:

Let’s say we had this user story:

As a snapshot photographer
I want some photo albums to be private
So that I have a backup of my personal photos online

And let’s say the product owner first expresses the Acceptance Criteria as rules:

  • Must have a way to set the privacy of photo albums
  • Private albums must be visible to me
  • Private albums must not be visible to others

We might discuss those to identify scenarios (as vertical slices through the above criteria):

  • Create new private album
  • Make public album private
  • Make private album public

Here, many teams would retain both acceptance criteria and scenarios. That’s ok but I’d only do that if we collectively understood that the information from these two will come together in the acceptance tests… And that whatever we agree in those acceptance tests supersede the previously discussed criteria.

This understanding tends to occur in highly collaborative teams. In newer teams, where disciplines (Business Analysts, Testers, Developers) are working more independently this tends to be harder to achieve.

In those situations (and often even in highly collaborative teams) I’d continue the discussion to iterate over the rules-oriented criteria to arrive at scenario-oriented criteria, carrying over any information captured in the rules, discarding the original rules-based criteria as we go. This might leave me with the following scenarios:

  • Create new private album (visible to me, not to others)
  • Make public album private (visible to me, not to others)
  • Make private album public (visible to me, & others)

Which, with a subtle change to the wording, become the acceptance criteria. I.e. the story is complete when we:

  • Can create new private album (visible to me, not to others)
  • Can make public album private (visible to me, not to others)
  • Can make private album public (visible to me, & others)

Once the story is ‘in-play’ (e.g. during a time-box/iteration/sprint) I’d elaborate these one at a time, implementing just enough to get each one passing as I go. By doing this we might arrive at:

Scenario: Can Create new private album
When I create a new private album called "Weekend in Brighton"
Then I should be able to see the album
And others should not be able to see it

Scenario: Can Make public album private
Given there is a public album called "Friday Night"
When I make that album private
Then I should be able to see the album
And others should not be able to see it

Scenario: Can Make private album public
Given there is a private album called "Friday Night"
When I make that album public
Then I should be able to see the album
And others should be able to see it

By being an elaboration of the scenario-oriented acceptance criteria there’s no implied need to also check the implementation against the original ‘rules-oriented’ criteria.

Agreeing that this is how we’ll work, it encourages more collaborative working – at least between the Business Analysts and Testers.

These new scenario-based criteria become the only means of determining whether the intent of the story has been fulfilled, avoiding much of the confusion that can occur when we have rules-oriented acceptance criteria as well as separate acceptance test scenarios.

In short, more often than not, I find these things much easier when the criteria and the scenarios are essentially one and the same.

Why not  give it a try?

Old Favourite – Sharks, Debts, Critical Mass and other reasons to Sustain Quality

This article originally featured on my old blog on 18th January 2010.

A while back I tweeted about critical mass of software:

Critical Mass of Code – past which the changeability of the code is infeasible, requiring that it be completely rewritten.

An elaboration of this might be:

Critical Mass of Software: the state of a software system when the cost of changing it (enhancement or correcting defects) is less economical than re-writing it.

This graph illustrates a hypothetical project where the cost of change increases over time (the shape of which reminds me of a thresher shark):

Note:The cost of a rewrite gradually grows at first to account for the delay between starting the re-write and achieving the same amount of functionality in the original version of the software at the same point in time. The gap between the cost-of-change and the cost-of-rewrite begins to decrease as the time it takes to implement each feature of comparable benefit in the original version grows.

It was just one of those thoughts that popped into my head. I soon discovered that critical mass of software is not a new idea.

One opportunity that I feel organisations miss out on is that this can be used as a financial justification for repaying technical debt, thus preventing or delaying the point at which software reaches its Critical Mass, or avoiding it altogether.

Maintaining quality combined with practices that keep the effort involved in completing each feature from growing over time can defer critical mass indefinitely:

Note: The cost of a rewrite is slightly less at first assuming that we are doing a little extra work to ensure that we get the infrastructure we need up and running to support sustainable change (e.g. continuous integration etc.)

This flat cost of change curve is one of the motivations of many agile practices and software craftsmanship techniques, such as continuous integration, test-driven-development, behaviour driven development and the continuous refactoring inherent in the latter two. A flat cost-of-change trend is good for the business, as they have more predictable expenditure.

The behaviour I’ve noticed with some teams is to knowingly accrue technical debt to shorten time to a near-future delivery in order to capitalise on an opportunity and then pay it back soon after:

This certainly defers reaching critical mass but it doesn’t prevent it.

Unfortunately, I see more teams taking on technical debt and not repaying it (for various reasons, often blamed on “the business” putting pressure on delivery dates).

If we had a way of estimating the point at which we’d reach critical mass, we’d be able to compare the benefit of repaying technical debt now in order to avoid or delay the cost of a rewrite… or even better, demonstrate the value of achieving a flatter cost of change.

I’m not sure that we have the data or the means of predicting it, but perhaps these illustrations of a hypothetical scenario will help you explain why sustaining constant quality, automating repeatable tests (or checking as some prefer to call it) wherever technically possible and, on those occasions when we do need to make a conscious choice to compromise quality to capitalise on an opportunity, that the debt is repaid soon after.

One company I know reached this point a couple of years ago and embarked on a department wide transformation to grow their skills in agile methods so that they not only re-wrote the software but could also avoid ever reaching critical mass again. A bold move, but one that paid off within a year. Even for them, they’ll need to avoid complacency as time goes on and not forget the lessons of the past. Let’s hope they do.

Old Favourite – Developer Race-Tech: Continuous Testing

The original version of this article appeared on my old blog on 28th April 2010. This version has had some edits…

Gearboxes in competitive motor racing are designed to shift as fast as possible. A competitive race-car has computer controlled, hydraulically activated gear shifts that change gears up or down faster than you can blink (literally)! In Formula One, each shift is so fast that the gearbox systems have been dubbed “seamless shift” gearboxes and can shift gear in around 2-4 100ths (0.02 – 0.04) of a second. Compare that to the circa 1-2 second gear-shift a competent driver takes to manually de-clutch, change gear and re-clutch on a road car. Even automatic gearboxes on road cars can’t keep pace with the rapid gear changes that a race car delivers.

Competitive Edge

The race car is only saving fractions of a second with each accelerated up-shift, but the race-driver changes gear so often per lap and there are so many laps in a race that these fractions of a second can add up to a vital and significant lead over their competitors.[1]
mclaren-mercedes

Set aside the lap-time improvements for a moment from spending at least half a second more on the power per up-shift than with a manual box… The modern F1 driver has much more to do in the cockpit too than the comparative tedium of changing gear [2].

Developer race-tech

Now, in motor racing, such gearboxes are taken for granted. No serious Formula One racing team would put their car on the track without one.

In a world where a lot of software development is for companies competing in the economical equivalent of a race, it seems that development teams aren’t taking full advantage of their own metaphorical millisecond gear-shifts.

There are tools that are a developer’s equivalent of a racing gearbox. The simplest example is background compilation. Other examples are refactoring tools that make widespread changes with a simple key-stroke. What once took minutes or hours with global find & replace or even scripting, we can complete in seconds. IDEs that automatically complete class-names and method names are another example. These are tools that many of us take for granted, like the racing driver and automated gear-shift.

Falling behind

But there are other places where we are still not taking full advantage of the technology. I am still encountering surprisingly few people using continuous testing tools, where tests are run automatically in the background every time a file is saved, and not just the test I’m working on, all my tests. There are a few tools available for this, including Infinitest and ZenTest.

Despite the availability of such tools, I still see many developers using keyboard shortcuts to execute tests. Or, worse, reaching for the mouse, right-clicking, navigating another menu level down and running the tests with a left-click, or worse still, forgetting to run them altogether. I want rapid feedback with minimum friction to obtaining it. Much like background compilation, unit tests should just run, and run often, alerting us when a problem occurs. The easier they are to run, the more likely we are to run them… How much easier could it be than it happening automagically each time we save a file?

Need for Speed

Try it for a while and, like me, even keyboard-shortcut executed tests start to feel like you’re stuck in traffic rather than being in a competitive race to the finish… Or, maybe it’s just me and my need for speed

 

The video is of me on the Silverstone Southern Circuit (part of the F1 GP circuit) taking my UK National Class B Racing License Test in a Nissan R35 GTR – approx 480+bhp, 0-62mph (0-100kmh) in 3.5secs, using it’s double-clutch, paddle-operated gear-shift providing gear changes in about 0.2 of a second. I passed… despite being very cautious on the brakes… and was noticeably quicker than the other person doing their test… which you see towards the end as I pass them 🙂

[1] At the Monaco GP, an F1 driver will change gear around 50-60 times in one lap. Over 78 laps, this adds up to as many as 4680 gear changes over the whole race (up and down-shifts).

[2] The comparative tedium of de-clutching, shifting and re-engaging the clutch is something that a race-driver should not need to worry about as they approach 200mph while adjusting the brake-balance lever, switching to a new fuel-air mixture setting, pressing the KERS boost button and/or deactivating the Drag Reduction System.