specification by example
DESCRIPTION
Lead by Example - How to Ensure Your Team Builds the Right Solution was presented at the 2012 DC Agile Engineering Conference on 12/7/2012 by Rebecca Halstead and Stephen Ritchie (@TRANSCRIPT
Lead by ExampleHow to ensure your team buildsthe right solution
How do you know that you have delivered the right solution?
What are the limitations of that approach?
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Specification by Example at the Office of Personnel Management
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Lead by Example
Building Testable
Requirements
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Exercise #1
Time how long it takes to understand the following:
◊ Yellow Circle
◊ Divide the circle into two sections – top and bottom
◊ In the top section, there are two black dots equidistant from the center
◊ In the bottom section, there is curved arc that dips in the center with two smaller curved arcs on each end of the larger arc
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Exercise #2
Time how long it takes to determine the calculation:
Annuity Supplement
The annuity supplement is computed as if you were age 62 and fully insured for a social security benefit when the supplement begins.
1. First, an estimate of what your full career (40 years of service) social security benefit would be is needed.
2. Then the actual amount of your civilian service is determined.
3. Finally, the estimated full career social security benefit is reduced by the employee’s actual service.
For example, if your estimated full career social security benefit would be $1,000 and you had worked 30 years under FERS, we would divide 30 by 40 (.75) and multiply ($1,000 x .75 = $750).
Annuity Supplement = Estimated Benefit x (Actual Years Service/40)
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Specification by Example
Specification by Example is a technique for ensuring that there is a shared understanding of what a given requirement, product backlog item, or a feature entails
1. Feature 2. User Story 3. Collaborate 4. Scenarios 5. Acceptance Criteria 6. Examples
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Example
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Develop a website that allows information about microchipped pets from multiple chip providers to be used for finding missing pets
As a registered pet owner, I want to search online,
So that I can know if my lost pet has been found
Product Backlog Allow companies to provide data Allow shelters and vet clinics to report a
missing pet Allow users to register their pet Allow pet owners to update their
contact information Alert pet owners if their pet has been
found Allow registered users to search for
missing pets...
Allow registered users to search for missing pets
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1. Feature 2. User Story 3. Collaborate 4. Scenarios 5. Acceptance Criteria 6. Examples
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Collaborate
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1. Feature 2. User Story
3. Collaborate 4. Scenarios
5. Acceptance
Criteria6. Examples
◊ Builds a shared understanding
◊ Prepare in advance to ensure similar domain knowledge
◊ Factors in other perspectives (e.g. business analyst, tester, developer)
Example: As a registered pet owner, I want to search online, so that I can know if my lost pet has been found.
Confirm and Clarify:1.Only registered users2.Microchip ID is unique3.Can search by Microchip ID,
Phone Number, and Email Address
4.Wildcard searches are not allowed, exact match only
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Define Scenarios
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1. Feature 2. User Story
3. Collaborate 4. Scenarios
5. Acceptance
Criteria6. Examples
◊ Scenarios are the outline
◊ Use plain language to describe the scenario
◊ Encourages conversation
◊ Helps determine if the story is sized right
Example: As a registered pet owner, I want to search online, so that I can know if my lost pet has been found.
Scenarios:1.Search with Results2.Search without Results
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AcceptanceCriteria
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1. Feature 2. User Story
3. Collaborate 4. Scenarios
5. Acceptance
Criteria6. Examples
Given a registered pet owner And their lost pet is in the databaseAnd their lost pet is flagged as foundWhen that pet owner searches by <search parameter>Then search results are returned
Given a registered pet ownerAnd (their lost pet is not in the database
OR (their lost pet is in the database AND not tagged as found)
OR the <search parameter> is invalid)When that pet owner searches by <search parameter>Then no search results are returned
And a message displays
Scenario #1: Search with Results
Scenario #2: Search without Results5
Example: As a registered pet owner, I want to search online, so that I can know if my lost pet has been found.
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AcceptanceCriteria (cont.)
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1. Feature 2. User Story
3. Collaborate 4. Scenarios
5. Acceptance
Criteria6. Examples
The conditions of satisfaction or acceptance criteria can be bullet points or described in a Given-When-Then template– One action ensures focus only on that action; direct cause and effect
relationship
– Express business functionality, not flows of interactions
Format:
Given [context]When [event]
Then [expected behavior]
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Examples
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1. Feature 2. User Story
3. Collaborate 4. Scenarios
5. Acceptance
Criteria6. Examples
Search Parameter(s) Search Result(s)
Microchip ID Phone Number Email Address Pet Name
A1297-98 Fluffy
703-555-1212 Ginger
[email protected] RalphB4318393 202-874-9855 Bingo
“…illustrating requirements using examples is a much more effective technique than specifying with abstract requirements. Because examples are concrete and unambiguous, they’re an ideal tool for making requirements precise – this is why we use them to clarify meaning in everyday communication.”
--Specification by Example, Gojko Adzic
Given a registered pet owner And their lost pet is in the databaseAnd their lost pet is flagged as foundWhen that pet owner searches by <search parameter>Then search results are returned
Scenario #1: Search with Results
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Tools
Tabular Style Requirements (data-centric) FitNesse (http://fitnesse.org/) Fit (http://fit.c2.com/) Concordion (http://www.concordion.org/) Robot Framework (http://code.google.com/p/robotframework/)
Behavior Driven Development (process-centric) Cucumber (http://cukes.info/) GreenPepper (http://www.greenpeppersoftware.com) easyb (http://www.easyb.org/) Selenium (http://seleniumhq.org/) RSpec (http://rspec.info/) SpecFlow (http://www.specflow.org/) JBehave (http://jbehave.org/) Twist (http://www.thoughtworks-studios.com/twist-agile-testing)
http://specificationbyexample.com/resources.html
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Concordion Example
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Concordion Example
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Contact Information
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Rebecca [email protected]://excella.com/people/rebecca-halstead.aspx
Stephen [email protected]://www.linkedin.com/in/sritchiehttp://www.excella.com/people/stephen-ritchie.aspx
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GROUP EXERCISE
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Group Exercise
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You are responsible for eliciting and documenting the requirements for your client’s new website, FaceSpace©, a competitor to Facebook. You start with the following features from the Product Backlog:
– Sign Up / Register– Add a Friend– Upload a Picture– Post a Status Update– Like a Status Update– Reply to a Friend's Status Update– Tag a Friend in a Picture– Update Your Profile
Group Exercise (cont.)
1. Define at least 3 scenarios2. Determine acceptance criteria for at least 1 scenario3. Identify examples that can validate the acceptance
criteria
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As a potential user, I want to sign-up for a FaceSpace account, so that I can customize my own FaceSpace page
1. Feature 2. User Story 3. Collaborate 4. Scenarios 5. Acceptance Criteria 6. Examples
User Story #1 - Scenarios
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As a potential user, I want to sign-up for a FaceSpace account, so that I can customize my own FaceSpace page
“Create Account” Scenarios
– Successful account creation– Username already taken– Incorrect email address format– Password does not meet security requirements– Passwords do not match
User Story #1 – Acceptance Criteria
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(1) Successful account creationGiven an unauthenticated user
When that user provides correct account sign-up data
Then an account is created
And a unique web page is created
And an email confirmation is sent
(2) Username already takenGiven an unauthenticated user
When that user provides a username that is associated to an existing FaceSpace account
Then an error message is presented to the user
User Story #1 – Acceptance Criteria (cont.)
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(3) Incorrect Email Address FormatGiven an unauthenticated user
When that user provides an incorrect email address
Then an error message is presented to the user
(4) Password does not meet security requirementsGiven an unauthenticated user
When a user provides <username>, <password>, <confirmation>
Then an error message is presented to the user
(5) Passwords do not matchGiven an unauthenticated user
When a user provides <username>, <password>, <confirmation>
Then an error message is presented to the user
User Story #1 - Examples
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Scenario Username Password Confirmation Email Address Message Result
1 rhalstead excella01! excella01! [email protected] Your personal site was successfully created.
Pass
2 rhalstead excella02! excella02! [email protected] The username entered is already in use. Please enter another username.
Fail
3 rhalstead99 excella03! excella03! ron.halsteadcompany.net Your email address is invalid. Fail4 rhalstead101 excella excella [email protected] Your password does not comply with
security requirements.Fail
5 zeus2000 excella05! excella05 [email protected] Your passwords do not match. Fail
5 zeus200 excella05! [email protected] Your passwords do not match. Fail