SE382 Software Engineering
Lecture 06
Agile Development (1)
First Midterm Exam





Tuesday, 3 March 2015 (same time as the lecture)
Duration: 75 minutes
Will cover all lectures delivered before the exam date
Will consist of MCQ’s, fill-in-the-blanks, questions with
short answers, and drawing of diagrams
If you miss any midterm exams for any reason, you will
have to appear for a makeup exam on the Thursday of
the last week of teaching. This exam will cover all
lectures delivered in the semester. It will consist of
drawing of diagrams and answering questions having
0.5-1 page answers.
Chapter 5

Agile Development
Slide Set to accompany
Software Engineering: A Practitioner’s Approach, 8/e
by Roger S. Pressman and Bruce R. Maxim
Slides copyright © 1996, 2001, 2005, 2009, 2014 by Roger S. Pressman
For non-profit educational use only
May be reproduced ONLY for student use at the university level when used in conjunction
with Software Engineering: A Practitioner's Approach, 8/e. Any other reproduction or use is
prohibited without the express written permission of the author.
All copyright information MUST appear if these slides are posted on a website for student
use.
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
3
The Manifesto for
Agile Software Development
“We are uncovering better ways of developing software
by doing it and helping others do it. Through this work
we have come to value:
Individuals & interactions over processes & tools
Working software over comprehensive documentation
Customer collaboration over contract negotiation
Responding to change over following a plan
That is, while there is value in the items on the right, we
value the items on the left more.”
Kent Beck et al
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
4
What is “Agility”?

Effective (rapid and adaptive) response to change

Effective communication among all stakeholders

Drawing the customer onto the team

Organizing a team so that it is in control of the
work performed
Yielding …

Rapid, incremental delivery of software
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
5
Agility and the Cost of Change
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
6
An Agile Process …

Is driven by customer descriptions of what is
required (scenarios)

Recognizes that plans are short-lived

Develops software iteratively with a heavy
emphasis on construction activities

Delivers multiple ‘software increments’

Adapts as changes occur
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
7
Agility Principles - I
1. Our highest priority is to satisfy the customer through
early and continuous delivery of valuable software
2. Welcome changing requirements, even late in
development. Agile processes harness change for
the customer's competitive advantage
3. Deliver working software frequently, from a couple
of weeks to a couple of months, with a preference
to the shorter timescale
4. Business people and developers must work together
daily throughout the project
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
8
Agility Principles - II
5. Build projects around motivated individuals. Give
them the environment and support they need, and
trust them to get the job done
6. The most efficient and effective method of conveying
information to and within a development team is
face–to–face conversation
7. Working software is the primary measure of progress
8. Agile processes promote sustainable development.
The sponsors, developers, and users should be able
to maintain a constant pace indefinitely
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
9
Agility Principles - III
9. Continuous attention to technical excellence and
good design enhances agility
10. Simplicity – the art of maximizing the amount of
work not done – is essential
11. The best architectures, requirements, and designs
emerge from self–organizing teams
12. At regular intervals, the team reflects on how to
become more effective, then tunes and adjusts its
behavior accordingly
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
10
Human Factors

The process molds to the needs of the people and
team, not the other way around

Key traits that must exist among the people on an
agile team and the team itself:
o Competence
o Common focus
o Collaboration
o Decision-making ability
o Fuzzy problem-solving ability
o Mutual trust and respect
o Self-organization
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
11
Extreme Programming (XP)
The most widely used agile process, originally
proposed by Kent Beck
XP activities:
1. Planning
2. Design
3. Coding
4. Testing
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
12
XP Planning
1. Begins with the creation of “user stories”
2. Agile team assesses each story and assigns a value
(priority) and a cost (in terms of development time)
3. Stories are grouped to for a deliverable increment
4. A commitment is made on delivery date
5. After the first increment “project velocity” is used to
help define subsequent delivery dates for other
increments
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
13
XP Design
1. Keep it simple
2. Encourage the use of CRC cards (see Chapter 10)
3. For difficult design problems, suggests the creation
of “spike solutions”—a design prototype
4. Encourages “refactoring”—an iterative refinement
of the internal program design
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
14
XP Coding and Testing
XP Coding
1. Recommends the construction of a unit-test for
a story before coding commences
2. Encourages “pair programming”
XP Testing
1. All unit-tests are executed daily
2. “Acceptance tests” are defined by the customer
and executed to assess customer visible
functionality
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
15
Extreme Programming (XP)
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
16
Industrial XP (IXP)

IXP has greater inclusion of management, expanded
customer roles, and upgraded technical practices

IXP adds six new practices to handle larger projects:
1. Readiness assessment - what’s required to do the project?
2. Project community - are the right people on the team?
3. Project chartering - to check feasibility
4. Test driven management - nonstop progress assessment
5. Retrospectives - to do increment postmortem
6. Continuous learning - to improve future increments
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
17
SE382 Software Engineering
Lecture 07a
Agile Development (2)
First Midterm Exam





Tuesday, 3 March 2015 (same time as the lecture)
Duration: 75 minutes
Will cover all lectures delivered before the exam date
Will consist of MCQ’s, fill-in-the-blanks, questions with
short answers, and drawing of diagrams
If you miss any midterm exams for any reason, you will
have to appear for a makeup exam on the Thursday of
the last week of teaching. This exam will cover all
lectures delivered in the semester. It will consist of
drawing of diagrams and answering questions having
0.5-1 page answers.
Scrum
Distinguishing features:
 Development work is partitioned into “packets”
 Testing and documentation are on-going as the
product is constructed
 Work occurs in “sprints” and is derived from a
“backlog” of existing requirements
 Meetings are very short and sometimes conducted
without chairs
 “demos” are delivered to the customer with the
time-box allocated
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
20
Fixed-Scope
Delivery

Deliver all features
that were promised
even if it delays the
increment

Customers
sometimes do not like
this because they
may have cleared
their schedules to
receive the increment
Time-Boxed
Delivery

Deliver the increment
on time, even if all
promised features
have not been
implemented

The delayed features,
if necessary, are
incorporated in future
increments
Scrum
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
22
Dynamic Systems Development Method


Similar to XP, but emphasizes project management
Guiding principles:
 Active user involvement is imperative
 Teams must be empowered to make decisions
 The focus is on frequent delivery of products
 Fitness for purpose is the acceptance criterion
 Iterative and incremental development is necessary
to converge on an accurate business solution
 All changes during development are reversible
 Requirements are baselined at a high level
 Testing is integrated throughout the life-cycle
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
23
DSDM Lifecycle
Who are the users?
Priotrized requirements
System architecture
Development plan
Identify functional requirements
Agree plan
Create functional prototype
Review functional prototype
Is it a good idea to build this product?
Should we use DSDM for this?
Cost/time estimates
Possible solutions and Risks
User approval guidelines
Deploy system
Train users
Review business impact
Identify non-functional requirements
Identify design prototype
Agree plan
Create/review design prototype
DSDM Lifecycle Image Ref: www.uwplatt.edu/files/csse/courses/prev/csse411-materials/s10/DSDM%20-%20bowersju.ppt
Why do we build models?

To better understand the details of the product
that needs to be built

To help break-up the product into smaller,
more manageable, and easy-to-build pieces

To help in the checking of what is being built
while it is been built
25
Agile Modeling (AM)
Agile models are more effective than traditional models
because they are just barely good, they don't have to be
perfect. AM follows the following principles:
 Model with a purpose (have a specific goal for AM)
 Use multiple models (each representing a specific
aspect of the system)
 Travel light (only keep those models that provide
value in the long run)
 Content is more important than representation
 Know the models and the tools used to create them
 Adapt locally (according to the needs of the team)
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
26
Agile Unified Process (AUP)

Simplified version of the Unified Process

It describes a simple, easy to understand
approach to developing software using agile
techniques and concepts yet still remaining true
to the Unified Process

AUP uses agile techniques including agile
modeling and test-driven development (creating
test-cases before commencing coding)
Ref: en.wikipedia.org/wiki/Agile_Unified_Process
AUP Activities
Each AUP iteration includes the following activities:
1. Modeling using UML
2. Implementation
3. Testing
4. Deployment of increment; acquisition of feedback
5. Configuration management
6. Project management
7. Management of the development processes & tools
These slides are designed to accompany Software Engineering: A Practitioner’s Approach, 8/e
(McGraw-Hill, 2014) Slides copyright 2014 by Roger Pressman.
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