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Agile Model Driven Development:
Techniques for Scaling Agile Delivery
Scott W. Ambler
Senior Consulting Partner
scott [at] scottwambler.com
twitter.com/scottwambler
Feel free to
ask questions
at any time
© Scott W. Ambler + Associates
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Agenda
•
•
•
What puzzles you?
Traditional versus agile development
A specification parable
•
•
•
What is modeling?
Agile Modeling
Agile models and documents
•
•
Agile Model Driven Development (AMDD)
Agile modeling and documentation practices
•
•
•
Modeling through the lifecycle
AMDD and scaling agile
Parting thoughts
© Scott W. Ambler + Associates
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Exercise: What Puzzles You?
• Organize into teams of 4-6 people
• Take a minute to introduce yourselves to one another
• For 5 minutes, discuss:
– What have you heard about modeling and documentation on agile
projects?
– What actual experiences do you have on agile project teams, if any?
– What puzzles you about agile modeling and documentation?
• A spokesperson from the team should be prepared to share one or
two things that puzzle you about agile modeling with the larger
group
© Scott W. Ambler + Associates
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Exercise: Traditional Versus Agile Greeting Cards
Organize into teams of 4-6 people
– Smaller is better, but you need at least 4 people
If possible:
– Work with people you have never met before
– Work with people from different organizations
– Have fun, but stay focused on the assignments
The overall strategy:
1. Get organized
2. Create a greeting card in a traditional manner
3. Create a greeting card in an agile manner
4. Discuss what happened
Step 1: Get Organized
• Choose roles:
–
–
–
–
1 stakeholder
1 analyst
1 tester
Everyone else is a developer
• The stakeholder from each group must come to the front of the room
for instructions.
• Everyone else:
– Read the next slide
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Step 2: A Birthday Card for Grandma
Model
3 min
Code
3 min
Test
• Analyst interviews stakeholder, producing requirements
document. Everyone else may listen but not speak.
• Analyst hands over requirements document to development
team. Analyst and Stakeholder now quiet.
• Developers create card. Tester watches.
• Developers provide card and original requirements document
to the tester.
• Tester inspects card and suggests improvements.
45 sec
Fix
45 sec
Rate
• Developers “fix” card.
• Developers provide card to the stakeholder.
• Stakeholder rates the end product.
Step 3: A Wedding Card for Friends
Develop
60 sec
Improve
30 sec
• You are in the same roles as before
• Organize the project into three short iterations
• Each iteration:
–
Develop
60 sec
Improve
30 sec
Develop
60 sec
Rate
–
Development (60 seconds):
• Anyone can ask the stakeholder questions.
• Anyone can work on the card
• Anyone can suggest improvements
Retrospective (30 seconds):
• At the end of each iteration identify how you can
together more effectively
• Choose one or two ideas to help improve your
approach next iteration
Step 4: Review
• What are your scores?
– Instructor will record on a flip chart
• As a team, take 5 minutes to discuss
–
–
–
–
–
–
What worked best for you? Why?
What are the risks with each approach?
What are the trade-offs with each approach?
Was there overhead between hand-offs? Why?
How efficient was each approach?
What can you apply to “the real world”?
• A spokesperson from the team should be
prepared to share some key learnings with the
larger group
A Specification Parable
Two years ago I asked for a toy like
the one my friends had. I didn’t know
what it was called so I described it to
Santa, hoping that he would know
what I was talking about.
My description:
It is a toy for kids. You get on it and you
bounce up and down. It is lots of fun.
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This is what I found under the tree.
It’s sort of fun, but it’s not what I wanted.
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Last year I asked Santa Claus for a sports car. It should be bright red
with some white detailing. It should have big racing tires so that it can
hug the road on sharp turns.
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This is what I found under the tree.
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This year I really want a
pony. So in my letter to
Santa Claus this year I am
going to be very clear that I
want a real, live pony. Not a
toy pony. The pony should
be white and between 7 and
9 feet tall. I will even include
this photo of the type of pony
that I would like with my
letter.
There will be no mistakes…
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Exercise: Specification
• Get back into your teams
• For 10 minutes, discuss within the team:
• Why didn’t he get the trampoline? How does this relate to what you’ve
seen in the workplace?
• Why didn’t he get the car he wanted? How does this relate to what
you’ve seen in the workplace?
• Assume that he gets the pony that he asked for. How will this actually
work out in practice? How does this relate to what you’ve seen in the
workplace?
• What approaches have you seen for eliciting requirements from
stakeholders? What were the advantages and disadvantages in the
long run?
• Someone needs to be a spokesperson for your team to share a few
key learnings with the rest of the group
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Exercise: What is a Model?
• Get back into your teams
• Goal:
• Define what a model is
• Capture your definition on an index card
• For 5 minutes, discuss within the team:
• What are models used for?
• Are sketches models?
• Are text-based artifacts (e.g. user stories and use
cases) models?
• Are tests models?
• Do you need tools to model? If so, what?
• Why do you model?
• A spokesperson should be prepared to share your
definition with the larger group
© Scott W. Ambler + Associates
Ummm...
not in our
context
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What is a Model?
A model is an abstraction that describes one or more aspects of
a problem or a potential solution addressing a problem
• Commonly one or more diagrams plus any corresponding
documentation
• How the abstraction is captured, if at all, shouldn’t matter
• Sketches should be considered models
• Non-visual artifacts can also be models
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Why Model?
To communicate
To think things through
To specify
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Primary Strategy for Modeling
No Modeling
Ad-Hoc
Sketch to Think and
Communicate
Sketch and Capture
Key Diagrams
SBMT for Docs
Traditional
Iterative
SBMT to Generate
Code
SBMT for Full Trip
Engineering
Agile
0%
20%
40%
60%
80% 100%
Source: Dr Dobb’s 2008 Modeling and Documentation Survey
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Exercise: Modeling in “non-Agile” Environments
• Get back into your smaller teams
• For 10 minutes, discuss:
–
–
–
–
–
–
–
What are your experiences with modeling on “non-agile” projects?
When did you model during the project?
How much modeling did you do?
What types of models did you create?
Who was involved with the modeling?
How were the models used?
What were the advantages and disadvantages of the approach?
• A spokesperson should be prepared to share a few key learnings
with the rest of the group
© Scott W. Ambler + Associates
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Exercise: Modeling in “Agile” Environments
• Get back into your smaller teams
• For 10 minutes, discuss:
–
–
–
–
–
–
–
What are your experiences with modeling on “agile” projects?
When did you model during the project?
How much modeling did you do?
What types of models did you create?
Who was involved with the modeling?
How were the models used?
What were the advantages and disadvantages of the approach?
• A spokesperson should be prepared to share a few key learnings
with the rest of the group
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Agile Modeling (AM)
• AM is a chaordic, practices-based
process for modeling and
documentation
• AM is a collection of practices
based on several values and
proven software engineering
principles
• AM is a light-weight approach for
enhancing modeling and
documentation efforts for other
software processes such as
Extreme Programming (XP),
Scrum, and Unified Process (UP)
Principles
Practices
Values
• AM is built right into Disciplined
Agile Delivery (DAD)
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What Are Agile Models?
• Agile models:
–
–
–
–
–
–
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As a student I want to
enroll in a course so
that I can complete my
degree
Fulfill their purpose
Are understandable
Are sufficiently accurate
Are sufficiently consistent
Are sufficiently detailed
Provide positive value
Are as simple as possible
• Agile models are just barely
sufficient!
Student
name
address
phoneNumber
emailAddress
studentNumber
averageMark
isEligible (name,
studentNumber)
getSeminarsTaken()
1
enrolled in
1..*
EnrollmentRecord
marksReceived
1..*
getAverageToDate()
getFinalMark()
{ordered, FIFO}
0..*
on waiting list
Professor
name
address
phoneNumber
emailAddress
salary
getInformation()
enrolled in
1
Seminar
name
seminarNumber
fees
0..* waitingList
addStudent(student)
0..* dropStudent(student)
instructs
0..1
?Some seminars may
not have an instructor?
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What are Agile Documents?
•
•
•
•
•
•
•
•
•
Focus on stable, not speculative
concepts
Are executable first, static only if you
have to
Maximize stakeholder ROI
Are concise
Fulfill a purpose
Describe information that is less likely
to change
Describe “good things to know”
Have a specific customer and
facilitate the work efforts of that
customer
Are sufficiently accurate, consistent,
and detailed
Just Barely
Good Enough
Ideal
Realistic
Value
Effort
Copyright 2005 Scott W. Ambler
Copyright 2012 Ambysoft Inc.
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Agile Model Driven Development (AMDD):
Project Level
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Exercise: Agile Requirements Envisioning
• Get back into your smaller teams
• Goal:
 Create a project profile focused on initial requirements envisioning
• Take 10 minutes to discuss:
 Identify the team member(s) who have been involved with an agile team
where some initial requirements envisioning occurred. If there are
several, quickly discuss each project and choose the one most
interesting to you
 Describe how the team approached initial requirements envisioning –
How much effort was it? What artifacts were created? Who was
involved? How was the output used by the team? How was the
architecture validated?
 Describe the project: How large was the team? Were you distributed?
What organizational challenges did you face?
 What are the advantages and disadvantages of what the team did?
Think short term and long term.
• A spokesperson will share a few key learnings with the larger group
© Scott W. Ambler + Associates
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Exercise: Agile Architecture Envisioning
• Get back into your smaller teams
• Goal:
 Create a project profile focused on initial architecture envisioning
• Take 10 minutes to discuss:
 Identify the team member(s) who have been involved with an agile team
where some initial architecture envisioning occurred. If there are
several, quickly discuss each project and choose the one most
interesting to you
 Describe how the team approached initial architecture envisioning –
How much effort was it? What artifacts were created? Who was
involved? How was the output used by the team? How was the
architecture validated?
 Describe the project: How large was the team? Were you distributed?
What organizational challenges did you face?
 What are the advantages and disadvantages of what the team did?
Think short term and long term.
• A spokesperson will share a few key learnings with the larger group
© Scott W. Ambler + Associates
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Agile Modeling’s Best Practices
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Test-Driven Development (TDD)
Test-First Development (TFD) is a
technique where you write a single test and
then you write just enough production code
to fulfill that test.
Refactoring is a technique where you make
a simple change to your code/schema to
improve its quality without changing its
semantics.
TDD = TFD + refactoring
© 2012 Scott W. Ambler + Associates
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Acceptance
and
Developer
TDD
Together
© 2012 Scott W. Ambler + Associates
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Some Industry Stats
• 2009 Agile Project Initiation Survey:
– 89% of agile teams do some sort of up-front requirements modeling
– 86% of agile teams do some sort of up-front architecture modeling
– 56% create a project vision/chart document
• 2008 Test-Driven Development Survey
– When it came to requirements capture, 85% of respondents wrote some
documentation, 53% did some modeling, and 45% wrote acceptance
tests
– When it came to design capture, 80% wrote documentation, 67%
modeled, and 57% wrote developer tests
• Survey details can be obtained free of charge at
Ambysoft.com/surveys/
© Scott W. Ambler + Associates
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Exercise: Adopting Test Driven Development (TDD)
• Get back into your smaller teams
• For 10 minutes, discuss:
–
–
–
–
Has your team adopted acceptance TDD (ATDD)? Is it considering it?
Has your team adopted developer TDD? Is it considering it?
What are the challenges associated with adoption of each form of TDD?
What are the benefits of each form of TDD? Think short term and long
term.
– What are the disadvantages? Think short term and long term.
• Someone needs to be a spokesperson for your team
• Be prepared to share with the larger group:
– Your adoption stats of ATDD and developer TDD (for each of ATTD and
developer TDD – Number doing it, thinking about it, Neither).
– A few key learnings from your discussion
© Scott W. Ambler + Associates
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The Basic/Agile Lifecycle of
Disciplined Agile Delivery (DAD)
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DAD Lifecycle: Advanced/Lean
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Exercise: Modeling and Documentation on an
Agile Project
• Get back into your teams
• Choose a type of project (described on following slides) that you will
take an disciplined agile approach with:
– Data warehouse
– Web site
– Pacemaker monitoring software
• For 10 minutes, discuss:
– How you would go about initial modeling. What are the primary models
that you would choose?
– What documents would you create and maintain throughout the project?
– How much detailed modeling you would need to do throughout this sort
of project?
• A spokesperson should be prepared to share key learnings with the
class
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Project Type: Data Warehouse
• Scenario:
– Your organization is in the process of developing a data warehouse
(DW) to support your business intelligence (BI) efforts.
– There are 17 sources of legacy data.
• Challenges:
– This is the third attempt at a DW. The previous two efforts took a
traditional, data-driven approach.
– The second project team was supported by a parallel Meta-Data
Management (MDM) project which was declared a success.
– The second version of the DW was deployed but few business
stakeholders found it useful.
– The data in the second DW was of good quality but didn’t support the
actual reporting needs of the stakeholders.
– The source data has the usual inconsistencies (semantic differences,
time differences,…)
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Project Type: Web Site
• Scenario:
– Your organization needs to redevelop its website.
– You want to add social media features, such as the ability to add
comments on some pages and the ability to vote on the usefulness of
pages, to the site.
– You want to allow customers to update their customer records via the
site. These records are currently stored in an internal CRM system.
• Challenges:
– All but two of the original development team have left your organization
to become agile coaches.
– The original team followed Scrum and believed they didn’t need to
create any sort of supporting technical documentation.
– The existing user interface (UI) design looks nice but usability of the site
is very poor due to poor flow between pages and poorly designed pages
in general.
– The existing solution uses technologies that aren’t on your enterprise
architecture road map
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Project Type: Pacemaker Monitoring Software
• Scenario:
– The latest generation of pacemakers are Bluetooth enabled.
– The goal is for someone to put their phone close to their chest so
that the pacemaker can either report its recent history to the person’s
doctor or if the pacemaker detects a serious problem it can call for
help.
– You are building the system that responds to the call made by the
pacemakers.
– The data upload packet from the pacemaker is in a well defined,
industry-standard format.
• Challenges:
– You are working in a life-critical environment.
– Your main competitor in the marketplace is already running beta
trials of a similar solution.
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Architecture Throughout the Lifecycle
Architectural vision
guides development
efforts
Architecture owner facilitates
architectural decisions
throughout the project
Architecture
spikes to explore
a technical issue
Architecture
handbook and
models updated as
required
Initial architectural
envisioning
Reduce risk early by proving the
architecture works
© 2012 Scott W. Ambler + Associates
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Analysis Throughout the Lifecycle
Discuss requirements
during iteration
planning/modeling
Active stakeholder
participation
throughout the project
Look-ahead
modeling for
upcoming complex
work items
Initial requirements
envisioning
Pre-project problem
exploration
Identify new needs
during demos
© Scott W. Ambler + Associates
Analyze
incoming
requests from
production
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Design Throughout Construction
Discuss design
implications during
iteration planning/modeling
Test-Driven Design
(TDD) throughout
Construction
Look-ahead
modeling for
upcoming complex
work items
Consider design
issues of incoming
requests from
production
© Scott W. Ambler + Associates
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DAD is Goal-Driven, Not Prescriptive
• There are various goals that a team needs to address throughout
the lifecycle
• For each goal there are several issues to consider
• For each issue there are different techniques to address it
• Each technique has its advantages and disadvantages
• Your choices depend on the context of the situation faced by a team
• Some “modeling-oriented” goals:
–
–
–
–
Explore the initial scope
Identify the initial technical strategy
Address changing stakeholder needs
Regularly produce a potentially consumable solution
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Goal: Explore the Initial Scope
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Goal: Identify Initial Technical Strategy
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Goal: Address Changing Stakeholder Needs
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Goal: Produce a Potentially Consumable Solution
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Goal: Move Closer to a Deployable Release
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Scaling/Tailoring Complexity Factors
Domain
Complexity
Straightforward
Geographic
Distribution
Team
Size
Very complex
Co-located
2
Technical
Complexity
Global
1000s
motivates
Straightforward
Very complex
motivates
Team
Culture
Organizational
Distribution
Single
Outsourcing
varies by
Compliance
affects
Agile
None
Rigid
Life critical
affects
Organizational
Culture
Agile
Rigid
© Scott W. Ambler + Associates
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Organizing Large Teams
Organizational options:
• Feature teams: A
subteam works on a
feature from end to
end.
• Component teams: A
subteam does all the
work for a specific
component.
• Internal open source:
A component is
developed via open
source techniques.
© Scott W. Ambler + Associates
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Exercise: AMDD and Team Size
• Get back into your teams
• Instructions:
– Take 15 minutes to discuss how you would approach modeling and
documentation for an agile team of 10 co-located people, a team of 30
people on the same floor, and a team of 100 people in the same
building
– Focus on how it would affect goals such as Explore the Initial Scope,
Identify Initial Technical Strategy, and Move Closer to a Deployable
Release
• A spokesperson will share with the larger group a few key learnings
© Scott W. Ambler + Associates
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Geographically Distributed/Dispersed Teams
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Exercise: AMDD and Geographic Distribution
• Get back into your teams
• Instructions:
– Take 15 minutes to discuss how you would approach modeling and
documentation for an agile team of 10 co-located people, a team of 10
people fully dispersed, and three teams of 10 people on three different
continents
– Focus on how it would affect goals such as Explore the Initial Scope,
Identify Initial Technical Strategy, and Address Changing Stakeholder
Needs
• A spokesperson will share with the larger group a few key learnings
© Scott W. Ambler + Associates
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Copyright 2012 Scott W. Ambler + Associates
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Challenges Adopting AMDD
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Modeling is an Important Aspect of Disciplined
Agile Delivery
• Disciplined agilists:
– Invest some up-front time exploring the initial scope
– Invest some up-front time identifying a viable technical strategy
– Work closely with enterprise professionals, including enterprise
architects and operations professionals, to ensure that what they’re
producing is enterprise compliant
– Tailor their approach to meet the context of the situation that they face
– Model throughout construction in a just-in-time (JIT) manner
– Document throughout construction because they realize that
documentation is part of their overall deliverable
– Work closely with their stakeholders whenever they can, not just with
stakeholder proxies such as product owners
© Scott W. Ambler + Associates
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AMDD at the Enterprise/Program Level
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The Value of Modeling
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Exercise: What Have You Learned?
• Individually, on a sheet of paper, answer the following questions:
– What three new things have you learned about modeling in general?
– What three new things have you learned about how modeling occurs on
an agile project?
– What improvements in the way you approach modeling and
documentation can you make on your current project team?
– What still puzzles you?
© Scott W. Ambler + Associates
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A Disciplined Ending….
Please…
– Take the opportunity to thank your teammates – we all learned together
– Fill out the workshop evaluation form(s)
– Turn in the evaluation(s) to the instructor
© Scott W. Ambler + Associates
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Thank You!
scott [at] scottwambler.com
Twitter: scottwambler
AgileModeling.com
AgileData.org
Ambysoft.com
DisciplinedAgileDelivery.com
EnterpriseUnifiedProcess.com
ScottWAmbler.com
© Scott W. Ambler + Associates
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Recommended Resources
61
© Scott W. Ambler + Associates
Backup Slides
© Scott W. Ambler + Associates
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AMDD and Large Teams
• Larger teams are often a response to greater domain complexity,
technical complexity, or cultural challenges
• Inception:
– You will likely need to invest a bit more time exploring the initial
requirements
– You may need to take an “API First” or “Contract Model” approach to
the architecture where you define the interface to components in detail
early in the project
– There will likely be a bit more initial specification
• Construction:
– Product Owners will need to coordinate requirement dependencies
– Architecture Owners will need to coordinate technical dependencies
– TDD may need to be enhanced with parallel independent testing
© Scott W. Ambler + Associates
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AMDD and Geographic Distribution
• Geographically distributed/dispersed teams are usually the result of
large teams or organizational culture
• Inception:
– You will likely need to invest a bit more time exploring the initial
requirements
– You will likely need to take an “API First” or “Contract Model” approach to
the architecture where you define the interface to components in detail
early in the project
– There will likely be a bit more initial specification
– Get key players together physically for Inception
• Construction:
–
–
–
–
–
Dispersed members will need to coordinate with their co-workers regularly
Product Owners will need to coordinate requirement dependencies
Architecture Owners will need to coordinate technical dependencies
TDD will likely need to be enhanced with parallel independent testing
Get key players together for critical milestones
© Scott W. Ambler + Associates
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AMDD and Compliance
• Inception:
– Invest time to understand the true implications of the regulations
regarding specification, documentation, and traceability
– The regulations MAY require more detailed requirements and
architecture specification, some traceability, and some level of formality
of validation of the specifications
• Construction:
– You may need to adopt more formal modeling and documentation
tooling
– You may need to keep all artifacts in sync throughout construction
– You may need to invest in traceability activities, or better yet in activities
and tooling that automatically result in sufficient traceability
– TDD may need to be enhanced with parallel independent testing
• Transition:
– You may need to hold final reviews and sign-offs of key artifacts
– You may need to generate final artifact manifests, traceability trees, and
so on
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