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Agilists want to
develop software which is both
high-quality and high-value, and
the easiest way to develop
high-value software is to
implement the highest priority
requirements first. This enables them
to
maximize stakeholder ROI.
Because
requirements change frequently
you need a streamlined, flexible approach to
requirements change management: In short, agilists strive to truly manage change, not to
prevent it.
Two versions of this practice are presented, a
simple strategy
promoted by Scrum and the more
disciplined
strategy followed by OpenUP. |
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Figure
1 overviews the agile approach to managing
requirements where
your software development team has a
stack of
prioritized
and
estimated requirements which
need to be addressed (Scrum
calls this prioritized stack a "product
backlog"). Each iteration (a "sprint" in
Scrum terminology) your team pulls an iteration's
worth of work off the top of the stack and commits to
implementing it by the end of the iteration.
New requirements are
prioritized by your
project stakeholders and added to
the stack in the appropriate place. Your project
stakeholders have the right to define new requirements,
change their minds about existing requirements, and even
reprioritize requirements as they see fit. However,
stakeholders must also be responsible for making
decisions and providing information in a timely manner.
Fundamentally a single person needs
to be the final authority when it comes to requirement
prioritization. In
Scrum this person is called the
product owner. Although there is often many project
stakeholders – end users, managers, architects,
operations staff, and so on – the product owner is
responsible for representing them all. On some projects
a
business analyst may take on this responsibility.
Whoever is in this role will need to work together with
the other stakeholders to ensure everyone is represented
fairly, often a difficult task. The priorities of non-requirement
work items are either negotiated by the team with
stakeholders or are addressed as part of slack time
within the schedule.
Figure 1. Agile requirements
management.
The approach depicted in
Figure
1 is fairly
simplistic, a reflection of Agile Process Maturity Model
(APMM) Level 1 thinking. We know that we do more than
just implement new requirements each iteration, we often
do non-requirement related work such as take training,
go on vacation, review products of other teams, address
defects (I believe that
defects are simply another type of requirement)
and so on. The point is that more than just
requirements need to be on the stack, we really need
work items. Furthermore, because we know that all
requirements, let alone work items in general, are not
created equal we shouldn't naively assume that we should
just wait to pull an iteration's worth of work off the
top of the stack at the beginning of the iteration.
What if a work item is very complex, requiring a bit
more thinking that what generally occurs in iteration
planning sessions? Disciplined agile teams will
adopt the
Model a Bit Ahead practice and look
an iteration or two down the work item stack and invest
the time to explore complex upcoming work items to
reduce their overall project risk.
Figure
2 overviews the
disciplined, APMM Level 2 approach to managing the work
items, and approach taken by the
Open Unified Process (OpenUP)
which reflects the real-world realities faced by agile
delivery teams.
Figure
2.
Disciplined agile
change
management
process.
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The Object Primer 3rd Edition: Agile Model Driven
Development with UML 2 is an
important reference book for agile modelers,
describing how to develop 35
types of agile
models including all 13
UML 2 diagrams.
Furthermore, this book describes the techniques
of the
Full Lifecycle Object Oriented Testing
(FLOOT) methodology to give you the fundamental
testing skills which you require to succeed at
agile software development. The book also
shows how to move from your agile models to
source code (Java examples are provided) as well
as how to succeed at implementation techniques
such as
refactoring and
test-driven development
(TDD). The Object Primer also includes a
chapter overviewing the critical database
development techniques (database refactoring,
object/relational mapping,
legacy analysis, and
database access coding) from my award-winning
Agile Database Techniques
book. |
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Agile Modeling: Effective Practices for Extreme
Programming and the Unified Process is the seminal
book describing how agile software developers approach
modeling and
documentation. It describes principles and
practices which you can tailor into your existing
software process, such as
XP, the
Rational Unified Process (RUP), or the
Agile Unified Process (AUP), to streamline your
modeling and documentation efforts. Modeling and
documentation are important aspects of any software
project, including agile projects, and this book
describes in detail how to
elicit requirements,
architect, and then
design your system in an agile manner. |
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The Elements of UML 2.0 Style describes a collection
of standards, conventions, and
guidelines
for creating effective
UML diagrams. They are based on sound, proven
software engineering principles that lead to diagrams
that are easier to understand and work with. These
conventions exist as a collection of simple, concise
guidelines that if applied consistently, represent an
important first step in increasing your productivity as
a modeler. This book is oriented towards
intermediate to advanced UML modelers, although there
are numerous examples throughout the book it would not
be a good way to learn the UML (instead, consider
The Object Primer). The book is a brief 188
pages long and is conveniently pocket-sized so it's easy
to carry around. |
I actively work with clients around the world to
improve their information technology (IT) practices as
both a mentor/coach and trainer. A full description of
what I do, and how to contact me, can be
found here.
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