Software Engineering_Agile Software Development By: Professor Lili Saghafi

Professor Lili Saghafi
proflilisaghafi@gmail.com
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By: Professor Lili Saghafi
May 8, 2020
University of Houston
UHD
@Lili_PLS
Software Engineering I
Software
Development
Lecture 3

2
Topics
• Software Development Models and their
processes (Review)
• Agile Software Development method
• Agile development Characteristic, Principals ,
lifecycle, stages
• Agile development techniques
• How it works
• Agile project management , Scrum
• Scaling agile methods , issues , Problems ,
maintenance , solutions , advantages

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Software Development
Methodology
• The waterfall model
– Plan-driven model. Separate and distinct phases of specification
and development.
• Incremental development
– Specification, development and validation are interleaved. May
be plan-driven or agile.
• Integration and configuration
– The system is assembled from existing configurable
components. May be plan-driven or agile.
In practice, most large systems are developed using a
process that incorporates elements from all of these
models.
• Agile Development

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Waterfall Model
5 phases in the waterfall model:
1. Requirements analysis and definition
2. System and software design (Output Design
Specification )
3. Implementation and unit testing ( Writing code ,
output is the software)
4. Integration and system testing Operation and
maintenance

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Waterfall Model
1. System Planning
2. System Requirement
3. System Design
4. System Implementation
5. System Maintenance and Support

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Waterfall Model
Drawback of the waterfall model is
the difficulty of accommodating
change
Used for large systems
engineering projects where a
system is developed at several
sites.

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The Requirements Engineering
Process

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A general model of the design
process

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Software Development Incremental development
Model• The cost of accommodating changing to customer
requirements is reduced.
• Easier to get customer feedback on the development
• Rapid delivery is possible
But:
• Managers need regular deliverables to measure
progress.
•• Regular changeRegular change tends to corrupt its structure.

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Integration and configuration Model
• Customization of COTS -Commercial-off-
the-shelf systems
• Reused elements may be configured to
adapt their behavior and functionality to a
user’s requirements
• Reuse is now the standard approach for
building many types of business system

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Example
• In billing system various modules can be
reused :
– Receives call detail and service usage
information, groups this information for
specific accounts or customers,
– Produces invoices, (based on Pricing
System)
– Creates reports for management,
– Records (posts) payments made to customer
accounts.

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Billing System
• Any billing system is a multi-branch, multi-cycle, multi-
currency, and multi-lingual modular system with various
components designed to manage the complete billing
cycle that includes:
– Applications,
– Meters reading,
– Invoicing,
– Collections (cash, checks, credit cards, bank accredits, and
tampering cases-electricity theft),
– Debts scheduling,
– Setup system,
– Security system,
– Mobile billing system

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Integration and configuration Model

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Types of Reusable Software
• Stand-alone application systems (sometimes
called COTS, Commercial-off-the-shelf systems)
that are configured for use in a particular
environment.
• Collections of objects that are developed as a
package to be integrated with a component
framework such as .NET or J2EE.
• Web services that are developed according to
service standards and which are available for
remote invocation.

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Agile Software Development
Manifesto
“Better ways of developing software by
doing it and helping others do it , Agile
software development comprises various
approaches to software development
under which requirements and solutions
evolve through the collaborative effort
of self-organizing and cross-functional
teams and their customer/end user”.

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The Need for Agile Development
• Rapid development (RAD) and delivery is
now often the most important
requirement for software systems
• Plan-driven development is essential for
some types of system but does not meet
these business needs.

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Agile Development Causes
• Dissatisfaction with the overheads
• to reduce overheads in the software
process (e.g. by limiting documentation)
and to be able to respond quickly to
changing requirements without
excessive rework.

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When to use Agile?
• Software company is developing a small
or medium-sized product for sale
• Custom system development , with clear
commitment from the customer to become
involved and few external rules and
regulations that affect the software.

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Agile History
• Agile development methods emerged in
the late 1990s whose aim was to radically
reduce the delivery time for working
software systems , that introduced a range
of agile development techniques

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Agile Development Characteristic
1. Program specification, design and
implementation are inter-leaved
2. The system is developed as a series of
versions or increments with stakeholders
involved in version specification and
evaluation
3. Frequent delivery of new versions for
evaluation
4. Extensive tool support (e.g. automated testing
tools) used to support development.
5. Minimal documentation – focus on working
code

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Plan-driven VS Agile
Development

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Reality
• In practice, most practical processes
include elements of both plan-driven and
agile approaches.
• There are no right or wrong software
processes.

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Why Agile?
• Due to its suitability for an ever-changing
business landscape, Agile Software
Development methodology has recently gained
significant attraction inside and outside of IT
departments.
• By adopting the Agile Software Development
Methodology, organizations are experiencing
great success in meeting the fast-paced change
of customer needs, offering an iterative
approach to the design and development of
software.

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Principles of Agile Methodology
• To satisfy the customer through early and
continuous delivery of valuable software is
the highest priority of Agile Software.
• With a preference to the shorter timescale,
from a couple of weeks to a couple of
months, delivering working software
frequently.

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• For the customer’s competitive advantage,
Agile processes harness change,
welcoming changing requirements, even
late in development.
• Working together of developers and
business people, daily throughout the
project.

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• Trust the motivated individuals to get the
job done, giving them the environment and
support they need, by building projects
around motivated individuals.
• Face to face conversation within a
development team by the most effective
and efficient method of conveying
information.

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• The primary measure of progress in
Working Software.
• To be able to maintain a constant pace
indefinitely by the developers, users and
sponsors sustainable development is
promoted by Agile processes.

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• Good Design and Technical excellence
enhance agility by continuous attention.
• The self-organizing teams give the best
architectures, requirements, and designs.
• The team adjusts its behavior and tunes
accordingly at regular intervals, reflecting
on how to become more effective.

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Important Features of Agile
Development Process
• Sprints: It is an iterative development
cycle, where requirements are refined
regularly by breaking down the work into
small and digestible chunks.
• Scrum Meetings: It is a highly
collaborative working style of the team.

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Important Features of Agile
Development Process
• Agile development process results in an
‘inspect and adapt’ approach with internal
and external stakeholders by reviewing
products and services frequently.
• Due to open interaction with investors and other
stakeholders and project management process,
the transparent process may be applied by
online Agile Project Management tools like
Team Foundation Service, Jira, Trello,
Kanbanzie, and others.

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Key Concepts of Agile Sprint
Processes
1. Daily Standup Meeting Checklist:
uses 4 Processes to planning well, managing
tightly and constantly optimizing sprints since
they are only two weeks.
first process being Daily Stand up, where all the
team members meet every day to make sure
that no team member is stuck on any problem
for more than few hours, keeping a check on
the progress of the sprint and taking care of
any problem.

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Processes
2. Sprint Turnover: is a process when
every two weeks the last sprint comes to a
close, as newsprint is planned, this
process is documented in order to avoid
any overlooked or unassigned issue.

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Processes
3. Sprint Retrospective: For improving the
way continuously, the team members run
agile processes, Sprint Retrospective is
vital. In this the team talks about three
points:
– Positive of Sprint Cycle?
– Negative of Sprint Cycle?
– How to Improve the Process.

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Processes
4. Sprint Estimation: Planning Poker method is used so
that the issues are carefully estimated and assigned so
that Sprints consists of a balanced and achievable
amount of work.
Each team member’s estimations are equally weighed by
the planning poker method.
Based on the amount of effort put to resolve the issue, the
story point is assigned to each issue.
Players put their card face down estimating points, instead
of speaking out their point loud, unless at the end they
reveal them.
To ensure that no issues get missed, and then informing
the team to begin Planning Poker, this estimation is
made.

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Processes
5. Pull Request Procedure: To avoid any risks to pull
requests, a lot of emphases is given by the development
team to make sure that it is done with care.
And every single pull request by using a procedure. The
process includes the following steps:
– For checking thoroughly.
– Producing a PR automatically in GitHub by pulling the
title of the checklist into GitHub as the pull request
name. This is done by inputting the checklist name
into a URL with a variable. To let others know about
the changes you have pushed to a branch in a
repository on GitHub, these requests are used.

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Processes
6. Pull Request Review Failed Procedure: The checklist
in this procedure helps the developers to follow if their
pull request has failed review, by strictly rectifying the
reasons for rejection, answering back with information
showing how you have re-checked and solved the
issues, and then again assigning the problem to a
manager for a next review.
It is easier to learn, having a lower level for error compared
to PR.
To ensure that the developers check the comments
on GitHub and Jira, they apply the changes, and then
review the issue which is basically the main goal of the
checklist.

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Processes
7. Pull Request Merge Process: Merge
Procedure is used for proving that it will
not break anything and only fix the issue
before a pull request can be merged and
approved into the olive branch.

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Processes
8. Weekly WordPress Maintenance: To
strengthen loopholes in the security of site,
EXP:WordPress maintenance is used.
We have to ensure that the plugins are
updated as soon as possible as updates of
Plugins and new releases of WordPress
often serve to fix security deeds.

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Processes
9. SSL Certificate Renewal: This process is used once in
three years but it is one of the most useful processes.
SSL Certificate allows secure connections from a web
server to a browser by activating the padlock and the
https protocol, when installed on a web server.
A cryptographic key is digitally bound to an organization’s
details by small data files known as SSL Certificates.
SSL renewal process is difficult but now it’s scheduled to
run automatically and send a notification so it can be
done quickly.

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Processes
10. Developer Onboarding: New developers are equipped
with onboarding tools and knowledge to be as efficient
as the rest of the team.
Previously by using proper processes it used to take 2-3
days of back and forth to start a journey of a developer
and a lot of sharing of screen is required, but now only
links to these processes are mailed to the developer,
and then they are watched as they fill the checklist up
and then get ready to go on their own.
For getting new hire set up, only one onboarding checklist
is used by JIRA, Trello, and all other tools used.

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Processes
• 11. How to Set Up Your Development
Environment : In this process, they will learn to
configure the template GitHub App by following
few steps and will learn how to run it over a
server.
• They will also learn Installation and how to
Authenticate as a GitHub App, and how these
authentication methods are different.
• Flexibility is essential when it comes to iterative
product development and the technology that
powers the projects.
• Every step of the way when you set up your
development environment manually should be
intervenable.
•

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Agile Software Development
Methodologies
• To adapt to change and deliver working software as
quickly as possible is the overall goal of each Agile
method
• there are variety of Agile Software development (or
system development ) methodologies including,
– Kanban,
– Disciplined Agile Delivery (DAD),
– Scrum,
– Adaptive Software Development,
– Scrumban,
– Dynamic Systems Development (DSDM),
– Extreme Programming (XP),
– Lean Software Development,
– Feature Driven Development,
– etc.

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Agile development Techniques
Agile Software Development Methodologies
• Extreme Programming (XP)
– New versions may be built several times per
day;
– Increments are delivered to customers every
2 weeks;
– All tests must be run for every build and the
build is only accepted if tests run
successfully.

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The five values of Extreme
Programming
1. Communication , no documentation but
communication
2. Simplicity, not thinking too far ahead into the future,
but focusing on the requirements of today , robust
enough to add the requirements the future
3. Feedback, from program , client and team.
4. Courage , different style of project management, and
be ready to be responsible, to renounce hierarchy and
be responsible and work without knowing
everything in the beginning itself
5. Respect, for others and the self. It also implies respect
for the code being written and for the client’s
expectations and needs.

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Examples of task cards for
prescribing medication

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Extreme Programming (XP)
• Test-first development, Testing is central to XP
and XP has developed an approach where the
program is tested after every change has
been made.
– Test-first development.
– Incremental test development from scenarios.
– User involvement in test development and validation.
– Automated test harnesses are used to run all
component tests each time that a new release is built.

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Test case description for dose
checking

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Problems with test-first development
• Programmers prefer programming to testing and
sometimes they take short cuts when writing tests.
• For example, they may write incomplete tests that do
not check for all possible exceptions that may occur.
• Some tests can be very difficult to write incrementally.
For example, in a complex user interface, it is often
difficult to write unit tests for the code that implements
the ‘display logic’ and workflow between screens.
• It difficult to judge the completeness of a set of tests.
Although you may have a lot of system tests, your test
set may not provide complete coverage.

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• Pair programming
– Pair programming involves programmers working in
pairs, developing code together.
– This helps develop common ownership of code and
spreads knowledge across the team.
– It serves as an informal review process as each line
of code is looked at by more than 1 person.
– It encourages refactoring as the whole team can
benefit from improving the system code.

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Agile Software Development Methodologies
Scrum
Scrum is an agile method that focuses on managing
iterative development rather than specific agile
practices.
There are three phases in Scrum.
1. The initial phase is an outline planning phase where
you establish the general objectives for the
project and design the software architecture.
2. This is followed by a series of sprint cycles, where
each cycle develops an increment of the system.
3. The project closure phase wraps up the project,
completes required documentation such as
system help framessystem help frames and user manualsuser manuals and
assesses the lessons learned from the project.

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Scrum terminology

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Scrum terminology

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Scrum sprint cycle

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Scrum Benefits
• The product is broken down into a set of
manageable and understandable chunks.
• Unstable requirements do not hold up progress.
• The whole team have visibility of everything and
consequently team communication is
improved.
• Customers see on-time delivery of increments
and gain feedback on how the product works.
•• TrustTrust between customers and developers is
established and a positive culture is created in
which everyone expects the project to succeed.

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Example:
• A software development project for a new
product, based on first-to-market advantage
has just been spotted on your company’s radar.
• Traditional methods of extreme programming,
where the client knows “exactly” what they want,
are out.
• Your team is small, and composed of young
professionals who are likely to respond well to a
radical project management model.

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What are your options in case of
agile methodology ?
• You’re likely to say, Agile Project
Management, of course! But which
methodology would you like to use?
• Scrum: that involves creating short
“sprints” based on the customer backlog
of tasks,focuses on a more flexible
approach to project management

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What are your options?
• Kanban, focuses on non-linear, iterative
methods of software development.
• Works on optimizing the pipeline of work.
Process evolved by the japanese , at the toyota
manufacturing plant to achieve just-in-time (JIT)
production which cuts costs and enables less
utilization of resources.
• Follows the “pull” principle of work, meaning that
tasks or products need to be “pulled” by
requirements and demand, and not “pushed”
from the top-down

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Traditional Project Management
In the case of a traditional project
management system if, for instance,
– There are 25 stories in total
– Analysts are able to handle five stories a
week
– Developers are able to handle five stories a
week
– Testers are limited to three stories a week

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Traditional Project Management
Board

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Kanban
In this situation, work simply piles up at the testers’
end. At the end of Week 1, the situation will be as
follows:
– Only three stories have moved on to deployment.
– Developers and analysts work on three stories, as
testers are unable to take the developers’ output
and test the same.
– Work gets piled up, leaving developers and
analysts and the project manager, in a fix.
– The Kanban method is an extremely simple
concept.
– It follows a simple logic of using a “pull method” to
removing the bottlenecks first, and limiting the
Works in Progress (WIPs) for better work
processes.

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What are your options?
• Extreme Programming, often abbreviated to XP,
which focuses on amplifying the positive
aspects of traditional programming models
so they work to their maximum potential.
• focused on meeting changing client
requirements.
• The first Extreme Programming project was
started in March 1996, by Kent Beck at Chrysler.

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Stages of Life Cycle
Agile Project Management
Part Two

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Stages of the
Agile Lifecycle
1. Concept/Objective: based on the client’s
requirement and interaction clearly clarifies the
client’s expectations
2. Inception/Identifying Requirement: initial
requirements , team? Fund? Modeling the
development using the architectural strategy
and flow charts.
3. Construction/Development/Iteration: team
now starts working on developing the software
based on the first iteration to produce a working
product with minimum functionality at the end of
the first sprint which then undergoes continuous
revisions improvements until finalized.

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Stages of the
Agile Lifecycle
4. Production & Testing:
– Testing and debugging of the system.
– Finishing the system development and user
documentation.
– Guiding and training users.
– Deploy the system.
5. Retirement: system has become obsolete. The
agile development lifecycle is all about
continuous evolving and emerging the
development cycle.

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Solutions
• Most projects include elements of plan-
driven andand agile processes

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Stages of the
Agile Lifecycle
1. Concept/Objective: based on the client’s
requirement and interaction clearly clarifies the
client’s expectations
2. Inception/Identifying Requirement: initial
requirements , team? Fund? Modeling the
development using the architectural strategy
and flow charts.
3. Construction/Development/Iteration: team
now starts working on developing the software
based on the first iteration to produce a working
product with minimum functionality at the end of
the first sprint which then undergoes continuous
revisions improvements until finalized.

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Stages of the
Agile Lifecycle
4. Production & Testing:
– Testing and debugging of the system.
– Finishing the system development and user
documentation.
– Guiding and training users.
– Deploy the system.
5. Retirement: system has become obsolete. The
agile development lifecycle is all about
continuous evolving and emerging the
development cycle.

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How Agile Development Works?
1. Firstly a team of testers, developers and
analysts are assembled known as a cross-
functional team. Then a Scrum is being used,
working very nearly with the Product
Owner/client to act as the head of the team.
2. Next plan important methods and projects in
three to four weeks, a Sprint Planning Meeting
takes place in the development cycle, where
needs are broken into tasks and hours to
provide software developers with a clear and
real path of success.

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3- When all the necessities of a project are
placed in the project backlog during” Sprint
Planning ” and then transferred to the
” sprint backlog ”.
Due to the feedback of stakeholder and
requirements of evolving business, the
product backlog is constantly growing and
prioritized again and again.

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4. To review work-in-progress during an
iteration Daily Scrums takes place for a
max of fifteen minutes.
Three main goals for stand-ups for each
team member is:
(a) What did you achieve yesterday?
(b) What is your goal for today?
(c) What hurdles are in your way?

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5. A ‘’task board’’ having columns and swim lanes
are what Daily Scrums typical revolve around.
To breakdown the key stages of the workflow, it
can have more than one column.
According to your team and your project the task
board can be structured– get creative! The
entire point of Agile is to be open and easy –
and not get ‘boxed in’.

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6. Sprint Retrospective and Sprint Review
meetings are held at the end of the sprint.
To get it accepted by the Product Owner,
the completed user stories and to ‘show
the world’ what you have achieved is what
the focus to Sprint review is.

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Agile project management
• The principal responsibility of software project
managers is to manage the project so that the
software is delivered on time and within the
planned budget for the project.
• The standard approach to project management
is plan-driven. Managers draw up a plan for the
project showing what should be delivered, when
it should be delivered and who will work on the
development of the project deliverables.

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Agile project management
• Agile project management requires a
different approach, which is adapted to
incremental development and the
practices used in agile methods.
• The informality of agile development is
incompatible with the legal approach to
contract definition that is commonly used
in large companies.

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Practical Problems With Agile
Methods
• Appropriate for new software development
rather than software maintenance. Yet
the majority of software costs in large
companies come from maintaining their
existing software systems.
• Designed for small co-located teams yet
much software development now involves
worldwide distributed teams.

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Agile Maintenance
• Lack of product documentation
• Keeping customers involved in the development
process
• Maintaining the continuity of the development
team
• Agile development relies on the development
team knowing and understanding what has to be
done.
• For long-lifetime systems, this is a real problem
as the original developers will not always work
on the system.

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System Development Issues
• How large is the system being developed?
– Agile methods are most effective a relatively small co-located
team who can communicate informally.
• What type of system is being developed?
– Systems that require a lot of analysis before implementation
need a fairly detailed design to carry out this analysis.
• What is the expected system lifetime?
– Long-lifetime systems require documentation to communicate
the intentions of the system developers to the support team.
• Is the system subject to external regulation?
– If a system is regulated you will probably be required to produce
detailed documentation as part of the system safety case.

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• How good are the designers and programmers
in the development team?
– It is sometimes argued that agile methods require
higher skill levels than plan-based approaches in
which programmers simply translate a detailed design
into code.
• How is the development team organized?
– Design documents may be required if the team is
distributed.
• What support technologies are available?
– IDE support for visualization and program analysis is
essential if design documentation is not available.

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• Traditional engineering organizations have a
culture of plan-based development, as this is the
norm in engineering.
• Is it standard organizational practice to develop
a detailed system specification?
• Will customer representatives be available to
provide feedback of system increments?
• Can informal agile development fit into the
organizational culture of detailed
documentation?

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Advantages of Agile
Development
1. Continuous Improvement: To improve the
future iteration, throughout the whole project,
agile encourages feedback from users and team
members.
2. Change is Embraced: As the planning cycles
are shorter, it is easy to accept changes and
accommodate at any point of time, throughout
the project.
3. End-Goal can be Unknown: For that kind of
projects where end-goal is not defined, Agile is
very beneficial. The goals will come to light as
the project processes.

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Advantages of Agile
Development
4. Faster, High-Quality Delivery: The team focuses on
high-quality development, collaboration, and testing, by
breaking down the project into manageable units. The
bugs get identified and solve more quickly by conducting
testing during each iteration.
5. Strong Team Interaction: To take responsibility and
own parts of the project, Agile highlights the importance
of team working together with frequent communication,
and face-to-face interaction.
6. Customers are Heard: By working very closely with the
project team, customers can gain a sense of ownership
and have a real impact on the end product by getting
many opportunities to see the work being delivered and
share their input.

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Conclusion
• Agile is good for midsize systems
• Agile is effective
• Agile system development works better
with Agile Project management

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References and Image credits
• https://www.educba.com
• https://hackernoon.com
• https://www.initio.eu/blog/2020/1/22/change-management-in-agile-
methodology
• Software Engineering, 10/E, Ian Sommerville, University of St
Andrews, Scotland
• Engineering Software Products: An Introduction to Modern Software
Engineering
– Ian Sommerville, University of St Andrews, Scotland
– ISBN-10: 013521064X • ISBN-13: 9780135210642
– ©2020 • Pearson • Paper, 352 pp
– Published 05/09/2019
• Introduction to Professional Engineering in Canada, Fifth Canadian
Edition, 5/E

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Any Question ?

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Software Engineering I
Software
Development
Lecture 3
By: Professor Lili Saghafi
May 8, 2020
University of Houston
UHD @Lili_PLS

Software Engineering_Agile Software Development By: Professor Lili Saghafi

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