sdlc or Software Development LifeCycle

Day 2

Testing Throughout SDLC

© Mahindra Satyam 2011

Learning Objectives
 Software Development Life Cycle

 Software Development Models
 Waterfall model
 V-model (Sequential Development Model)

 Iterative-incremental Development Model

 Agile Methodology

2

Software Development Life Cycle
 The Software Development Life Cycle is a step-by-step process involved in the
development of a software product.

 The whole process is generally classified into a set of steps and a specific
operation will be carried out in each of the steps.

 The basic classification of the whole process is as follows:


Initial



Analysis



Design



Coding



Testing



Maintenance

Initial:
• The main aim of the initial phase is requirements gathering.
• The responsible person is “BA – Business Analyst”
• The outcome document name is “BRS – Business Requirements
Specification”.
3

Contd..
Analysis:
• In this phase requirements are analyzed for the feasibility of implementation.
• Planning the project, Resource estimation, Schedule preparation, project prototype
will takes place.
• The outcome document name is “SRS – System Requirements Specification”.
• At the end of this phase, both project plan and test plan documents are delivered.

Design:
•
•
•
•
•

The aim is to create the architecture of the total system(including database design).
Dividing the system into no. of module and sub-modules.
Preparing Data-flow diagrams, Control-flow diagrams, Use cases.
Designing Database
The outcome document name is “TDD – Technical Design Document”.

Coding:
• In this phase, programmers prepares/write the code for given specification in
the chosen programming language.
• The outcome is “Source code”.
4

Contd..
Testing:
• In this phase, testing team will execute the prepared test cases on the given
build/system.
• Main aim is, to verify that the given system working as per client requirements.
• If test fails, they will raise an incident.
• The outcome documents are: Test Cases, Incidents.

Maintenance:
•
•
•
•

In this phase, the system deployed into the client‟s environment.
Any issue raised by client, environmental problems are handled.
Requirements change requests are handled
Maintenance is made up of:
• Corrective maintenance
• Ex: fixing customer-reported problems
• Adaptive maintenance
• Ex: making the software run on a new version of an OS or Database.
• Preventive maintenance
• Ex: changing the application program code to avoid a potential security hole in an
OS code

5

Software
Development Models


Waterfall Model


Software Development Models – Waterfall model
Waterfall Model

Requirements

 In "The Waterfall" approach, the
whole process of software
development is divided into
separate process phases.

Design

 All these phases are cascaded to
each other so that second phase is
started as and when defined set of
goals are achieved for first phase
and it is signed off, so the name
"Waterfall Model".

Code

 All the methods and processes

Testing

undertaken in Waterfall Model are
more visible.

Release
8

Contd..
Advantages

Disadvantages

 It is the simplest software process

 All requirements must be known

model in terms of complexity and
ease of implementation. As you
know, it is nothing but common
sense.

upfront

 Jumping back and forth between
two or more phases is not possible.

 The next phase can be reached only

 This model is extremely easy to

after the previous one has been
completed.

understand and therefore, is
implemented at various project
management levels and in a number
of fields (not just software
development).

 Bugs and errors in the code cannot
be discovered until and unless the
testing phase is reached. This can
lead to a lot of wastage of time and
other precious resources.

 It employs a systematic, orthodox
method of project development and
delivery.

 Not suitable for projects wherein the
project requirements are dynamic or
constantly changing.

9

V -Model


V-Model

11

Contd..
 A framework to describe the software development lifecycle activities from
requirements specification to maintenance. The V-model illustrates how testing
activities can be integrated into each phase of the software development lifecycle.

 The V-Model demonstrates the relationships between each phase of the
development life cycle and its associated phase of testing.

 Testing helps to ensure that the work-products are being developed in the right
way (verification) and that the product will meet the user needs (validation).

Verification
• Checks that the work-product meets the requirements set out for it.
• Verification helps to ensure that we are building the product in the
right way.

Validation
• Checks that the behavior of the work-product matches the customer
needs as defined for the project.
• Validation helps to ensure that we are building the right product as far
as the users are concerned.
12

Contd..
V-Model Objectives:

Minimization of Project Risks

Improvement and Guarantee of Quality

Reduction of Total Cost over the Entire Project and System Life Cycle

Improvement of Communication between all Stakeholders

13

Contd..
Advantages

Limitations

 The users of the V-Model participate in

 The organization and execution of







the development and maintenance of the
V-Model.
A change control board publicly
maintains the V-Model.
The change control board meets once a
year and processes all received change
requests on The V-Model.
At each project start, the V-Model can be
tailored into a specific project V-Model,
because the V-Model is project
independent.
It provides concrete assistance on how
to implement an activity and its work
steps, defining explicitly the events
needed to complete a work step: each
activity schema contains instructions,
recommendations and detailed
explanations of the activity.

operation, maintenance, repair and
disposal of the system are not covered
by the V-Model. However, planning and
preparation of a concept for these tasks
are regulated in the V-Model.

 The V-Model addresses software
development within a project rather than
a whole organization.

14

Iterative-Incremental
Model


Iterative-Incremental Model
 This is one where the requirements do not need to be fully defined before coding
can start. Instead, a working version of the product is built, in a series of stages,
or iterations - hence the name iterative or incremental development.

16

Contd..
 An Iterative model for development has fewer steps those are:


1) Define Iteration Requirements



2) Build Iteration



3) Test Iteration

 This type of development is often referred to as cyclical - we go „round the
development cycle a number of times‟, within the project.

 Example:
– Assuming a development of a social networking website with parts like
member registration, sign in, forgot password, member profile, search
members, friends list, blog, blog search, photos, photo search and messaging.

 Development:
– First iteration comprising of member registration, sign in, member profile and
search members.

– The second iteration can comprise of friends list, blog, blog search.
– The third iteration can comprise of photos, photo search, messaging and
forgot password.
17

Contd..
 Drawbacks:
 The lack of formal documentation makes it difficult to test.
 The working environment may be such that developers make any changes
required, without formally recording them.

 The amount of testing required to ensure that implementation of the changes
does not cause unintended changes to other parts of the software (this is
called regression testing).

18

Agile Testing


What is Agile Testing ? –Agile values
Core value1: Individuals and interactions over
processes and tools:
• Undocumented process with good interactions among
the stakeholders, than a documented process with
less interactions
Agile Values
(Agile
Manifesto)

How it is
different?

Roles and
Activities

Core value 2: Working software over comprehensive
documentation:
• Running code is ruthlessly honest

Whole team
approach

Core value 3: Customer collaboration over contract
negotiation:
• Customer is part of development process; it is
collaboration in decision meeting, speed of
communication and individual's connect
Core value 4: Respond to change over following a plan:
• Rather than focusing on outdated plan, deal with
changing realities

20

Water fall model –Success factors
Complexity = f( development+ target) environment variables

Successful:
The system is
useful when it
is delivered

21

Agile – Success factors

Risk reduction:
analyzing,
prioritizing and
attacking the top
risks in each
iteration

Walker Royce, Software project management: A unified framework, 1998, AW
22

What is Agile Testing –Meaning whole Team approach
 Business facing tests –tests that describe customer‟s desired features and
functionalities

 It includes functional, system, load, performance, stress, security, usability ..
 Agile testing –does not mean testing on an agile project. Testing is inline with
valuing working software and responding to change

 In Agile not only testers or a quality assurance team own the responsibility for
quality –but entire team
 We just don‟t think of departments -rather the skills and resources we need to
deliver the best possible product.
 Business facing tests –tests that describe customer‟s desired features and
functionalities

 Focus of agile development is producing high quality software in a time frame that
maximizes its value to the business.
 Any task might be completed by any team member or a pair of team members
 Team takes the responsibility of all kinds of testing tasks, such as automating
tests and manual exploratory testing
23

Agile Testing –Roles and Activities
Customer Team
• Includes business experts, product owners, domain
experts, product managers, business analysts, Subject
Matter experts
• Customer team writes the stories or feature sets that the
developer team delivers
• They communicate and collaborate with the developer
team through out each iteration
• Testers are integral part of the customer team helping
elicit requirements and examples and helping the
customers express their requirements as tests, make
sure the tests pass, and make sure that adequate
regression tests are automated

Developer Team
• Involved in delivering code
• Discourage specialized roles on the teams and
encourage all team members to transfer their skills to
other members as much as possible
• Testers are also on the developer team

Interaction of roles

24

Programmer

Tester

Domain Expert

How Agile Testing is different?

I1

Requirements

I2

I3

I4

Software
Specifications

E
D
C

Code
C

Testing

A

Release

25

B

A

B

A

D
C
B

A

B

Traditional Vs Agile Testing
 In water fall model, testing happens towards the end, right before release
 It appears that there is as much time for testing as coding –but in reality it is
not the case –Testing gets squished because coding takes longer time than
expected

 Requirements are taken as inputs and tests are created from a requirement
document

 Agile is incremental with intermediate releases
 Testers test each increment of coding as soon as it is finished (An iteration can
be as short as one week or one month)

 Team builds and tests little bit of code, make sure that it works correctly and
then moves on to the next piece of requirements that need to be built.

 A story is not “done” until it has been tested
 One team might be dedicated to a single project or might be part of another
project

 Tests normally created by business analysts before anyone ever thought of
writing a line of code. It is collaborative effort.
26

Ten Principles for Agile Tester
Agile Tester is a professional tester who embraces change,
collaborates well with both development and business team
• Agile testers tend to have good technical skills
• collaborate with others to automate tests, are also experienced exploratory testers
• better understand customer‟s requirements

10 Principles important for agile testers:
• Provide continuous feedback: Feedback helps the team in removing impediments
• Deliver value to the customer: Tester helps the team in limiting the scope and recognizes impact of
cool features to the story
• Enable face to face communication: Any time there is a question about how a feature should work,
tester can pull in a programmer and a business expert to talk about it.
• Have courage: It is a core value in XP such as test automation; continuous integration allow the
team. We need courage to let ourselves fail, learn quickly from that; allow others to make
mistakes, to seek help –when we‟ve blown up an iteration because we didn‟t get a stable build, we
will start thinking of ways to ensure it does not happen again
• Keep it simple: Take a simple approach to ensuring that the software meets requirements
• Practice continuous improvement
• Respond to change
• Self organize
• Focus on people
• Enjoy
27

Thank you

mahindrasatyam.com
Safe Harbor
This document contains forward-looking statements within the meaning of Section 27A of the Securities Act of
1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking
statements contained herein are subject to certain risks and uncertainties that could cause actual results to differ
materially from those reflected in the forward-looking statements. Mahindra Satyam undertakes no duty to
update any forward-looking statements.

28

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