Role of Testing in Software Development Life Cycle

Full text

© 2019, IJCSE All Rights Reserved 886
International Journal of Computer Sciences and Engineering Open Access
Research Paper Vol.-7, Issue-5, May 2019 E-ISSN: 2347-2693
Role of Testing in Software Development Life Cycle
Nirali Honest
Smt. Chandaben Mohanbhai Patel Institute of Computer Applications,CHARUSAT,Changa
*Corresponding Author: niralihonest.mca@charusat.ac.in,
DOI: https://doi.org/10.26438/ijcse/v7i5.886889 | Available online at: www.ijcseonline.org
Accepted: 08/May/2019, Published: 31/May/2019
Abstract— People search for quality in every artifact they come across. The concept of quality has also entered in the area of
software development where it becomes crucial to thoroughly check the software system at different levels of testing. Now-a-
days the competition is increased highly and the frequency of changes in platforms and business requirements are also very
high, so for a software to be stable and in use for long run, requires to support and update based on the current requirements.
Software testing is one of the umbrella activities performed at any organization to provide value and quality, to ensure the
longitivity of software product in the market. This paper covers the concept of testing, its role in assuring quality, test cases,
levels of testing, methods of testing and test planning, executing and monitoring. The papers emphasize on the use and impact
of test driven environment with concept of story board based implementation.
Keywords — Software testing, Software quality, Test Driven Environment.
I. INTRODUCTION
Introduction
The concept of quality did not originate with software
systems [8]. It started with as an impact of Global
competition, Outsourcing, growing customer outlooks, have
brought the concept of quality to the considerably
highlighted. Initially the quality movement started in Japan
with the concept of Statistical Quality Control (SQC)
methods. Statistical quality control is a discipline based on
measurements and statistics. Decisions and Plans are made
and based on the gathering and calculation of the actual data
in the form of different metrics, the past experience or
intuition is not considered as the major way of doing the
work. A working model based on the concept of forming a
Strategy, Prepare and Organize to work as per the strategy,
Assess the work and Manage changes was adopted where
initially a plan or strategy was established to set the objective
and process to deliver the results, then implement the plan
and measure its performance, and then assess the
measurements and report the results to decision makers, and
Apply changes if required to improve the process. Basically
quality concept started with one unit in the organization, but
then it moved to the entire organization. This caused the
move from SQC to TQC (Total Quality Control) in Japan.
With the acceptance of quality standards to be enforced in
the entire organization various quality related activities were
introduced in the organization like audits, quality circle
promotion of quality management principles and quality
control. One of the innovative TQC methodologies
developed in Japan is referred to as cause-and-effect model.
This was also called as the Ishikawa model and it is used to
understand the causes that has effect on the quality of the
product. The Software Quality is defined as “An effective
software process applied in a manner that creates a useful
product that provides measurable value for those who
produce it and those who use it”. Effective testing is very
important to perform which include minimum test cases with
maximum cover [1]. Testing is a costly activity if not carried
out optimally, and its aim is to find defects from systems
with critical and catastrophic events [2][3][4]. There are two
important terms used in testing which include „Validation‟
and „Verification‟. Verification activity helps us in assessing
a software system by determining whether the product of a
given development phase satisfies the requirements
established before the start of that phase. One may note that a
product can be an intermediate product, such as requirement
specification, design specification, code, user manual, or
even the final product. Activities that check the correctness
of a development phase are called verification activities.
Validation Activities help us in confirming that a product
meets its intended use. Validation activities aim at
confirming that a product meets its customer‟s expectations.
In other words, validation activities focus on the final
product, which is extensively tested from the customer point
of view. Validation establishes whether the product meets
overall expectations of the users. Validation is done at the

International Journal of Computer Sciences and Engineering Vol.7(5), May 2019, E-ISSN: 2347-2693
© 2019, IJCSE All Rights Reserved 887
end of the development process and takes place after
verifications are completed [5]. The testing activities are
challenging activities and a proper roadmap is to be decided
before proceeding to testing [9][10].
II. ROLE OF TESTING IN SOFTWARE QUALITY
Testing plays a significant role in accomplishing and
evaluating the quality of a software product [13]. Software
quality assessment can be divided into two broad categories,
namely, static and dynamic analysis. Static Analysis means,
it is based on the examination of a number of documents,
namely requirements documents, software models, design
documents, and source code, etc. Basic methods used in
static analysis includes code review, inspection, walk-
through, algorithm analysis, and proof of correctness. It does
not involve actual execution of the code under development.
Dynamic Analysis: Dynamic analysis of a software system
involves actual program execution in order to expose
possible program failures. The behavioral and performance
properties of the program are also observed. Programs are
executed with both typical and carefully chosen input values.
Often, the input set of a program can be impractically large.
The major objectives of testing include, a. The system will
work properly, b. The system will not work properly, c.
Reduce the risk of system breakdown, and d. Reduce the cost
of testing.
The first objective covers the test cases to check the system
will work properly with all specified operations this test
intend to check the basic flow of use case model and it
covers the positive testing scenario, the second objective
covers the test cases to make the system fail, so check all the
alternative flows specified during the use case model and it
covers the negative testing scenario, the third objective
covers the test cases to fail or crash the system explicitly, to
know the limit and boundaries of system, so likewise the
maximum system capacity in terms of processing speed,
memory allocations, interrupt handling, etc. can be known,
the fourth objective focuses on designing of minimum test
cases to cover the maximum system testing, it is near to
impossible to test all the combination of test cases ,so the
challenge of testing is to cover entire system testing with
minimum number of test cases and utilize the resources
optimally with reducing the cost associated with it. The test
case generation is one of the most important task in testing.
[15]. A test case is a simple pair of <input, expected
outcome>. In stateless systems: output completely depends
on the input, example includes to compute the cube of
numbers, user simply needs to provide input to the system. In
state-oriented systems: output of one sequence act as an input
to another sequence and so on, example includes a telephone
switching system and ATM machine, etc. The test cases can
be formed from different sources of information as a
software development process produces a large number of
artifacts, such as requirements specification, design
document, and source code. In order to generate effective
tests at a lower cost, test designers study and analyze the
various sources of information like, Requirements and
functional specifications, Source code, Input and output
domains, Operational profile, and a fault model which
predict the incorrectness in the system. From this model, a
designer can predict the consequences of particular faults. In
order to test a program, a test engineer must perform a
sequence of testing activities that include, identify an
objective to be tested, select inputs, compute the expected
outcome, set up the execution environment of the program,
Execute the program, Analyze the test result.
III. LEVELS OF TESTING
Testing is performed at different levels involving the
complete system or parts of it throughout the life cycle of a
software product.
Figure 1: Levels of Testing
In Unit level testing the individual units/components are
tested in a standalone manner. The purpose is to validate that
each unit of the software performs as designed without any
dependency. Integration Testing is a level of the software
testing process where individual units are combined and
tested as a group. The purpose of this level of testing is to
expose faults in the interaction between integrated units.
System testing is a level of the software testing process
where a complete, integrated system/software is tested. The
purpose of this test is to evaluate the system‟s agreement
with the specified requirements and Acceptance testing is a
level of the software testing process where a system is tested
for acceptability. The purpose of this test is to evaluate the
system‟s compliance with the business requirements and
assess whether it is acceptable for delivery.
Unit Test
System Test
Integration
Test
Acceptance
Test
Test Individual
parts of system
Group the parts of system and test
gradually
Test the system customer
requirements
Test the whole
system

International Journal of Computer Sciences and Engineering Vol.7(5), May 2019, E-ISSN: 2347-2693
© 2019, IJCSE All Rights Reserved 888
IV. METHODS OF TESTING
Two broad concepts in testing, for test design, are white-box
and black-box testing [6][7]. White-box testing techniques
are also called structural testing techniques. As the name
implies this testing methodology provides the insight into the
application and create test cases. The tester has the source
code structure and other details of application available, so
based on it the test cases can be prepared. It enables to see
what is happening inside the application. For example,
consider a system Bank ATM machine, here the code behind
the system, would be to provide operations for pin
verification, listing menu items, check balance, withdraw
cash, link aadhar card, etc. As part of white box testing the
tester focus on working of each module correctly, before it is
tested using the user interface. Here the main source of input
for test cases is the underlying structure of the source code.
This method of testing can be applied at unit level and
integration level testing where the code is developed and
tested in parallel. Black-box testing techniques are called
functional testing techniques. As the name implies the tester
is not provided with an insight of the application that is being
tested [11][12]. The tester understands the requirements and
test them using the user interface of the system. The tester is
not aware of the code behind the interface being tested. This
testing methodology looks at what are the available inputs
for an application and what the expected outputs are that
should result from each input. For example, consider a
system Bank ATM machine, the tester understands the
possible operations supported by the ATM, prepares the set
of inputs and expected outcomes to test each operation, at the
time of testing the tester has access of user interface only, the
source code is not made available to the tester. Here the main
source of input for test cases is number of inputs and
expected outputs to test the user interface. This method of
testing can be applied at system level testing where all the
interfaces are prepared and tested for each functionality. The
main difference between black-box and white-box testing is
the areas on which they choose to focus. In simplest terms,
black-box testing is focused on results. If an action is taken
and it produces the desired result, then the process that was
actually used to achieve that outcome is irrelevant. White-
box testing, on the other hand, is concerned with the details.
It focuses on the internal workings of a system and only
when all paths have been tested and the sum of an
application‟s parts can be shown to be contributing to the
whole is testing complete.
V. TEST PREPARATION AND POLICY
The purpose of system test preparation includes setting the
test planning, to get ready and organized for test execution
[14]. A test plan provides a framework, scope, details of
resource needed, effort required, schedule of activities, and a
budget. In earlier days the traditional testing concept was
followed as shown in figure 2, where testing is done at the
end, this has direct impact on the time and cost of the
software which is not feasible, it is interesting to note that a
new test-centric approach to system development is
gradually emerging. This approach is called test-driven
development (TDD). In test-driven development,
programmers design and implement test cases before the
production code is written as shown in figure 3. This
approach is a key practice in modern agile software
development processes such as eXtreme Programming (XP).
The XP is a software development methodology which is
used to improve software quality and responsiveness to
changing customer requirements.
Figure 2 : Traditional concept of testing.
Figure 3 : Test Driven Development in testing.
Extreme programming” (XP) champions the use of tests as a
development tool, and it supports the “Test First”
functionality. Here the requirement are taken up as stories
and they are written on the story board, one story at a time is
written to meet the functionalities and the code to test the
story is also written, once the test is passed and meet all the
requirements from a given story, the next story from the
story board is taken, and it continues up to all the stories are
written and tested as shown in figure 4.
Figure 4: Testing the functionalities in a test driven
environment.

International Journal of Computer Sciences and Engineering Vol.7(5), May 2019, E-ISSN: 2347-2693
© 2019, IJCSE All Rights Reserved 889
The main features of agile software development practices
include Incremental development means to divide the
software life-cycle development into “multi-waterfall” cycle
and with every cycle the testing is contributing to the
changes that need to be incorporated, the Unit testing is done
by the programmers, and acceptance testing done by
customers, on more frequent basis regression testing is done
to make sure that the changes made in the code, database,
etc. to support the new requirements do not disturb or cause
problems in already existing code. It also focuses on writing
test code for one test case at a time, before the final code is
written. After the test planning and design monitoring and
measurement are two key principles in software testing.
Different software matrices are created to store and analyze
the results. Software Testing Matrix is a quantitative
measure of the degree to which a system, component, or
process possesses a given attribute. Test execution metrics
can be broadly categorized into two classes as Metrics for
monitoring test execution and Metrics for monitoring defects.
Quantitative evaluation is carried out through measurement.
Testing is a distributed activity conducted at different levels
throughout the life cycle of a software. In testing, team is
organized and managed Unit-level tests are generally
developed and executed by the programmers. System
integration testing is performed by the system integration test
engineers. A team for performing system-level testing is
truly separated from the development team, and it usually has
a separate head count and a separate budget. However, the
real user acceptance testing is executed by the client‟s special
user group. The user group consists of people from different
backgrounds, such as software quality assurance engineers,
business associates, and customer support engineers
including the major stakeholders of the customer
organization.
Conclusion and Future Scope
The paper covers the concept of testing, its role in software
development cycle, methods of testing, level of testing and
preparing test cases. In the current competitive era, for a
software product to sustain in market for long time, it is
mandatory to have good quality and value. Following the
test driven environment can help to work testing first mean
while the production code is being written.
ACKNOWLEDGMENT
I would like to thank Charotar University of Science and
Technology to provide with all the resources required to carry
out the work in this paper.
REFERENCES
[1] P. Ron. Software testing. Vol. 2. Indianapolis: Sam‟s, 2001.
[2] S. Amland, "Risk-based testing:" Journal of Systems and Software,
vol. 53, no. 3, pp. 287–295, Sep. 2000.
[3] Redmill and Felix, “Theory and Practice of Risk-based Testing”,
Software Testing, Verification and Reliability, Vol. 15, No. 1,
March 2005.
[4] B. Agarwal et al., “Software engineering and testing”. Jones &
Bartlett Learning, 2010.
[5] Mailewa, Akalanka, Jayantha Herath, and Susantha Herath. "A
Survey of Effective and Efficient Software Testing." The Midwest
Instruction and Computing Symposium. Retrieved from
http://www.micsymposium.
org/mics2015/ProceedingsMICS_2015/Mailewa_ 2D1_41. pdf.
2015.
[6] Mohd. Ehmer Khan, “Different Approaches to White Box testing
Technique for Finding Errors,” IJSEIA, Vol. 5, No. 3, pp 1-13,
July 2011.
[7] Mohd. Ehmer Khan, “Different Approaches to Black Box Testing
Technique for Finding Errors,” IJSEA, Vol. 2, No. 4, pp 31-40,
October 2011.
[8] L. Osterweil. Strategic directions in software quality. ACM
Computing Surveys, 4:738–750, Dec. 1996.
[9] A. Bertolino. Software testing research: Achievements, challenges,
dreams. In 2007 Future of Software Engineering, pages 85–103,
2007.
[10] M. J. Harrold. Testing: A roadmap. In Proceedings of the
Conference on the Future of Software Engineering, pages 61–72,
2000.
[11] M.Kumar, S.K.Singh,. R.K.Drivedi, “A Comparative Study of
Black Box Testing and White Box Testing Techniques”,
International Journal of Advance Research in Computer Science
and Management Studies, Volume-3, Issue 10,pp. 32-44,October
2015, ISSN: 2321-7782
[12] M.E. Khan, “Different Approaches to Black Box Testing
Technique for Finding Errors”, IJSEA, Volume- 2, Issue- 4, pp 31-
40, October 2011.
[13] Oluigbo I.V., Asiegbu B.C., Ezeh G.N., Nwokonkwo O.C.,
"Group Membership Prediction of an Outsourced Software
Project: A Discriminant Function Analysis Approach",
International Journal of Scientific Research in Multidisciplinary
Studies , Vol.3, Issue.4, pp.12-18, 2017.
[14] Suresh Jat and Pradeep Sharma, “Analysis of Different Software
Testing Techniques “,International Journal of Scientific Research in
Computer Science and Engineering Vol.5, Issue.2, pp.77-80, April
2017.
[15] Chandraprakash Patidar ,“Test Case Generation Using Discrete
Particle Swarm Optimization Algorithm”, International Journal of
Scientific Research in Computer Science and Engineering ISSN 2320-
7639 Volume-1, Issue-1, Jan- Feb-2013.
Authors Profile
Nirali Honest is working as an Assistant Professor, at Smt. Chandaben
Mohanbhai Patel Institute of Computer Applications, since August 2005.
She has completed her Master of Computer Applications from Gujarat
University in 2005 and Bachelor of Computer Applications in 2002 form
Dharamsinh Desai University. During her tenure at academics she has
conducted sessions on various courses like Software Quality Assurance,
Software Engineering and Quality Assurance, Web Technologies and
Applications, Database Management Concepts, System Analysis and
designing , Network Technologies, Object Oriented Designing and
Modeling, Parallel Processing, Operating Systems, Object Oriented concepts
and programming in java, Computer based management systems, Data
Structures, Fundamentals of Commerce and Business Processes. She has
completed her Ph.D. in Computer Science and Applications in
November,2016, her area of work is Web Usage Mining. She has
published/presented thirteen research papers in national/ international
journals/conferences of repute.