software-testing-framework 3

Software Testing Framework
Document version: 2.0

Harinath V Pudipeddi
hari.nath@sqae.com
http://www.sqae.com

Table of Contents

Table of Contents ...........................................................................................2
Revision History .............................................................................................4
Testing Framework .........................................................................................5

1.0 INTRODUCTION ........................................................................................................................... 5

1.2 TRADITIONAL TESTING CYCLE ...........................................................................5

2.0 VERIFICATION AND VALIDATION TESTING STRATEGIES................................... 6

2.1 VERIFICATION STRATEGIES ..............................................................................6
2.1.1 REVIEW’ S ......................................................................................7
2.1.2 INSPECTIONS ..................................................................................8
2.1.3 WALKTHROUGHS ..............................................................................8
2.2 VALIDATION STRATEGIES ................................................................................8

3.0 TESTING TYPES ............................................................................................................................ 9

3.1 WHITE BOX TESTING .....................................................................................9
W HITE BOX TESTING TYPES................................................................................. 10
3.1.1 BASIS PATH TESTING ...................................................................... 10
3.1.2 FLOW GRAPH N OTATION ................................................................... 10
3.1.3 CYCLOMATIC COMPLEXITY ................................................................. 10
3.1.4 GRAPH MATRICES .......................................................................... 10
3.1.5 CONTROL STRUCTURE TESTING ........................................................... 10
3.1.5.1 Condition Testing ........................................................... 10
3.1.5.2 Data Flow Testing .......................................................... 10
3.1.6 LOOP TESTING ........................................................................................ 11
3.1.6.1 Simple Loops .......................................................................... 11
3.1.6.2 Nested Loops .......................................................................... 11
3.1.6.3 Concatenated Loops ................................................................. 11
3.1.6.4 Unstructured Loops .................................................................. 11
3.2 BLACK BOX TESTING ................................................................................... 11
BLACK BOX TESTING TYPES ................................................................................. 11
3.2.1 GRAPH BASED TESTING METHODS ....................................................... 11
3.2.2 EQUIVALENCE PARTITIONING .............................................................. 11
3.2.3 BOUNDARY VALUE ANALYSIS .............................................................. 12
3.2.4 COMPARISON TESTING ..................................................................... 12
3.2.5 ORTHOGONAL ARRAY TESTING ............................................................ 12
3.3 SCENARIO BASED TESTING (SBT).......................................................... 12
3.4 EXPLORATORY TESTING ....................................................................... 13
4.0 STRUCTURAL SYSTEM TESTING TECHNIQUES ........................................................ 13
5.0 FUNCTIONAL SYSTEM TESTING TECHNIQUES......................................................... 13

4.0 TESTING PHASES ...................................................................................................................... 14

4.2 UNIT TESTING ........................................................................................... 15
4.3 INTEGRATION TESTING ................................................................................. 15
4.3.1 TOP- DOWN I NTEGRATION.................................................................. 15

Software Testing Framework V2.0 2 of 25

4.3.2 BOTTOM- UP I NTEGRATION ................................................................. 15
4.4 SMOKE TESTING......................................................................................... 16
4.5 SYSTEM TESTING ........................................................................................ 16
4.5.1. RECOVERY TESTING ....................................................................... 16
4.5.2. SECURITY TESTING ........................................................................ 16
4.5.3. STRESS TESTING .......................................................................... 16
4.5.4. PERFORMANCE TESTING .................................................................. 16
4.5.5. REGRESSION TESTING .................................................................... 17
4.6 ALPHA TESTING ......................................................................................... 17
4.7 USER ACCEPTANCE TESTING ........................................................................... 17
4.8 BETA TESTING ........................................................................................... 17

5.0 METRICS ......................................................................................................................................... 17

6.0 TEST MODELS .............................................................................................................................. 19

6.1 THE ‘V’ MODEL .......................................................................................... 19
6.2 THE ‘W’ MODEL ......................................................................................... 20
6.3 THE BUTTERFLY MODEL ................................................................................ 21

7.0 DEFECT TRACKING PROCESS.............................................................................................. 23

8.0 TEST PROCESS FOR A PROJECT ........................................................................................ 24

9.0 DELIVERABLES ........................................................................................................................... 25


Revision History

Version No. Date Author Notes
1.0 August 6, 2003 Harinath Initial Document Creation and Posting on
web site.
2.0 December 15, Harinath Renamed the document to Software
2003 Testing Framework V2.0
Modified the structure of the document.
Added Testing Models section
Added SBT, ET testing types.

Next Version of this framework would include Test Estimation Procedures and More
Metrics.


Testing Framework

Through experience t hey det erm ined, t hat t here should be 30 defect s per 1000 lines
of code. I f t est ing does not uncover 30 defect s, a logical solut ion is t hat t he t est
process was not effective.

1.0 Introduction

Test ing plays an im port ant role in t oday’s Syst em Developm ent Life Cycle. During
Testing, we follow a systematic procedure to uncover defects at various stages of the
life cycle.

This fram ework is aim ed at providing t he reader various Test Types, Test Phases,
Test Models and Test Met rics and guide as t o how t o perform effect ive Test ing in t he
project.

All t he definit ions and st andards m ent ioned in t his fram ework are exist ing one’s. I
have not alt ered any definit ions, but where ever possible I t ried t o explain t hem in
sim ple words. Also, t he fram ework, approach and suggest ions are m y experiences.
My int ent ion of t his fram ework is t o help Test Engineers t o underst and t he concept s
of t est ing, various t echniques and apply t hem effect ively in t heir daily work. This
framework is not for publication or for monetary distribution.

I f you have any queries, suggest ions for im provem ent s or any point s found m issing,
kindly write back to me.

1.2 Traditional Testing Cycle

Let us look at t he t radit ional Soft ware Developm ent life cycle. The figure below
depicts the same.

Requirements Requirements

Design Design
Te st

Code Code

Test Maintenance

Maintenance

Fig A Fig B

I n t he above diagram ( Fig A) , t he Test ing phase com es aft er t he Coding is com plet e
and before the product is launched and goes into maintenance.


But , t he recom m ended t est process involves t est ing in every phase of t he life cycle
( Fig B) . During t he requirem ent phase, t he em phasis is upon validat ion t o det erm ine
t hat t he defined requirem ent s m eet t he needs of t he proj ect . During t he design and
program phases, t he em phasis is on verificat ion t o ensure t hat t he design and
program s accom plish t he defined requirem ent s. During t he t est and inst allat ion
phases, t he em phasis is on inspect ion t o det erm ine t hat t he im plem ent ed syst em
meets the system specification.

The chart below describes the Life Cycle verification activities.

Life Cycle Phase Verification Activities
Requirements • Determine verification approach.
• Determine adequacy of requirements.
• Generate functional test data.
• Determine consistency of design with requirements.
Design • Determine adequacy of design.
• Generate structural and functional test data.
• Determine consistency with design
Program (Build) • Determine adequacy of implementation
• Generat e st ruct ural and funct ional t est dat a for
programs.
Test • Test application system.
Installation • Place tested system into production.
Maintenance • Modify and retest.

Throughout the entire lifecycle, neither development nor verification is a straight- line
act ivit y. Modificat ions or correct ions t o a st ruct ure at one phase will require
modifications or re- verification of structures produced during previous phases.

2.0 Verification and Validation Testing Strategies

2.1 Verification Strategies

The Verificat ion St rat egies, persons / t eam s involved in t he t est ing, and t he
deliverable of that phase of testing is briefed below:

Verification Performed By Explanation Deliverable
Strategy
Requirements Users, Developers, Requirement Reviewed and
Reviews Test Engineers. Review’s help in approved
base lining desired statement of
requirements to requirements.
build a system.
Design Reviews Designers, Test Design Reviews help System Design
Engineers in validating if the Document,
design meets the Hardware Design
requirements and Document.
build an effective
system.
Code Walkthroughs Developers, Code Walkthroughs Software ready for
Subject Specialists, help in analyzing the initial testing by
Test Engineers. coding techniques the developer.
and if the code is
meeting the coding
standards

Code Inspections Developers, Formal analysis of Software ready for
Subject Specialists, the program source testing by the
Test Engineers. code to find defects testing team.
as defined by
meeting system
design specification.

2.1.1 Review’s

The focus of Review is on a work product ( e.g. Requirem ent s docum ent , Code et c.) .
Aft er t he work product is developed, t he Proj ect Leader calls for a Review. The work
product is dist ribut ed t o t he personnel who involves in t he review. The m ain
audience for t he review should be t he Proj ect Manager, Proj ect Leader and t he
Producer of the work product.

Major reviews include the following:
1. In Process Reviews
2. Decision Point or Phase End Reviews
3. Post Implementation Reviews

Let us discuss in brief about t he above m ent ioned reviews. As per st at ist ics Reviews
uncover over 65% of t he defect s and t est ing uncovers around 30% . So, it ’s very
important to maintain reviews as part of the V&V strategies.

In- Process Review
In- Process Review looks at t he product during a specific t im e period of a life cycle,
such as act ivit y. They are usually lim it ed t o a segm ent of a proj ect , wit h t he goal of
ident ifying defect s as work progresses, rat her t han at t he close of a phase or even
later, when they are more costly to correct.

Decision- Point or Phase- End Review
This review looks at t he product for t he m ain purpose of det erm ining whet her t o
cont inue wit h planned act ivit ies. They are held at t he end of each phase, in a
sem iform al or form al way. Defect s found are t racked t hrough resolut ion, usually by
way of t he exist ing defect t racking syst em . The com m on phase- end reviews are
Software Requirements Review, Critical Design Review and Test Readiness Review.

• The Soft w a r e Re qu ir e m e n t s Re vie w is aim ed at validat ing and
approving t he docum ent ed soft ware requirem ent s for t he purpose of
est ablishing a baseline and ident ifying analysis packages. The
Developm ent Plan, Soft ware Test Plan, Configurat ion Managem ent Plan
are some of the documents reviews during this phase.

• The Cr it ica l D e sign Re vie w baselines t he det ailed design specificat ion.
Test cases are reviewed and approved.

• The Te st Re a din e ss Re vie w is perform ed when t he appropriat e
applicat ion com ponent s are near com plet ing. This review will det erm ine
the readiness of the application for system and acceptance testing.

Post Implementation Review
These reviews are held aft er im plem ent at ion is com plet e t o audit t he process based
on act ual result s. Post - I m plem ent at ion reviews are also known as Postmortems and
are held t o assess t he success of t he overall process aft er release and ident ify any
opport unit ies for process im provem ent . They can be held up t o t hree t o six m ont hs
after implementation, and are conducted in a format.

There are three general classes of reviews:
1. Informal or Peer Review
2. Semiformal or Walk- Through
3. Format or Inspections

Pe e r Re vie w is generally a one- to- one m eet ing bet ween t he aut hor of a work
product and a peer, init iat ed as a request for im port regarding a part icular art ifact or
problem . There is no agenda, and result s are not form ally report ed. These reviews
occur on an as needed basis throughout each phase of a project.

2.1.2 Inspections
A knowledgeable individual called a m oderat or, who is not a m em ber of t he t eam or
t he aut hor of t he product under review, facilit at es inspect ions. A recorder who
records the defects found and actions assigned assists the moderator. The meeting is
planned in advance and m at erial is dist ribut ed t o all t he part icipant s and t he
part icipant s are expect ed t o at t end t he m eet ing well prepared. The issues raised
during t he m eet ing are docum ent ed and circulat ed am ong t he m em bers present and
the management.

2.1.3 Walkthroughs
The aut hor of t he m at erial being reviewed facilit at es walk- Through. The part icipant s
are led t hrough t he m at erial in one of t wo form at s; t he present at ion is m ade wit hout
int errupt ions and com m ent s are m ade at t he end, or com m ent s are m ade
t hroughout . I n eit her case, t he issues raised are capt ured and published in a report
dist ribut ed t o t he part icipant s. Possible solut ions for uncovered defect s are not
discussed during the review.

2.2 Validation Strategies

The Validat ion St rat egies, persons / t eam s involved in t he t est ing, and t he
deliverable of that phase of testing is briefed below:

Validation Performed By Explanation Deliverable
Strategy
Unit Testing. Developers / Test Testing of single Software unit
Engineers. program, modules, ready for testing
or unit of code. with other system
component.
Integration Testing. Test Engineers. Testing of integrated Portions of the
programs, modules, system ready for
or units of code. testing with other
portions of the
system.
System Testing. Test Engineers. Testing of entire Tested computer
computer system. system, based on
This kind of testing what was specified
usually includes to be developed.
functional and
structural testing.
Production Developers, Test Testing of the whole Stable application.
Environment Engineers. computer system
Testing. before rolling out to
the UAT.

User Acceptance Users. Testing of computer Tested and
Testing. system to make sure accepted system
it will work in the based on the user
system regardless of needs.
what the system
requirements
indicate.
Installation Test Engineers. Testing of the Successfully
Testing. Computer System installed
during the application.
Installation at the
user place.
Beta Testing Users. Testing of the Successfully
application after the installed and
installation at the running
client place. application.

3.0 Testing Types
There are two types of testing:

1. Functional or Black Box Testing,
2. Structural or White Box Testing.

Before t he Proj ect Managem ent decides on t he t est ing act ivit ies t o be perform ed, it
should have decided t he t est t ype t hat it is going t o follow. I f it is t he Black Box,
t hen t he t est cases should be writ t en addressing t he funct ionalit y of t he applicat ion.
I f it is t he Whit e Box, t hen t he Test Cases should be writ t en for t he int ernal and
functional behavior of the system.

Funct ional t est ing ensures t hat t he requirem ent s are properly sat isfied by t he
applicat ion syst em . The funct ions are t hose t asks t hat t he syst em is designed t o
accomplish.

Structural testing ensures sufficient testing of the implementation of a function.

3.1 White Box Testing
Whit e Box Test ing; also know as glass box t est ing is a t est ing m et hod where t he
tester involves in testing the individual software programs using tools, standards etc.

Using white box testing methods, we can derive test cases that:
1) Guarant ee t hat all independent pat hs wit hin a m odule have been exercised at
lease once,
2) Exercise all logical decisions on their true and false sides,
3) Execute all loops at their boundaries and within their operational bounds, and
4) Exercise internal data structures to ensure their validity.

Advantages of White box testing:
1) Logic errors and incorrect assum pt ions are inversely proport ional t o t he
probability that a program path will be executed.
2) Oft en, a logical pat h is not likely t o be execut ed when, in fact , it m ay be execut ed
on a regular basis.
3) Typographical errors are random.


White Box Testing Types
There are various t ypes of Whit e Box Test ing. Here in t his fram ework I will address
the most common and important types.

3.1.1 Basis Path Testing
Basis pat h t est ing is a whit e box t est ing t echnique first proposed by Tom McCabe.
The Basis pat h m et hod enables t o derive a logical com plexit y m easure of a
procedural design and use t his m easure as a guide for defining a basis set of
execut ion pat hs. Test Cases derived t o exercise t he basis set are guarant eed t o
execute every statement in the program at least one time during testing.

3.1.2 Flow Graph Notation
The flow graph depict s logical cont rol flow using a diagram m at ic not at ion. Each
structured construct has a corresponding flow graph symbol.

3.1.3 Cyclomatic Complexity
Cyclom at ic com plexit y is a soft ware m et ric t hat provides a quant it at ive m easure of
the logical complexity of a program. When used in the context of a basis path testing
m et hod, t he value com put ed for Cyclom at ic com plexit y defines t he num ber for
independent pat hs in t he basis set of a program and provides us wit h an upper
bound for t he num ber of t est s t hat m ust be conduct ed t o ensure t hat all st at em ent s
have been executed at lease once.
An independent pat h is any pat h t hrough t he program t hat int roduces at least one
new set of processing statements or a new condition.

Computing Cyclomatic Complexity
Cyclom at ic com plexit y has a foundat ion in graph t heory and provides us wit h
extremely useful software metric. Complexity is computed in one of the three ways:
1. The num ber of regions of t he flow graph corresponds t o t he Cyclom at ic
complexity.
2. Cyclomatic complexity, V(G), for a flow graph, G is defined as
V (G) = E- N+2
Where E, is the number of flow graph edges, N is the number of flow graph nodes.
3. Cyclomatic complexity, V (G) for a flow graph, G is also defined as:
V (G) = P+1
Where P is the number of predicate nodes contained in the flow graph G.

3.1.4 Graph Matrices
The procedure for deriving t he flow graph and even det erm ining a set of basis pat hs
is am enable t o m echanizat ion. To develop a soft ware t ool t hat assist s in basis pat h
testing, a data structure, called a graph matrix can be quite useful.
A Graph Mat rix is a square matrix whose size is equal to the number of nodes on the
flow graph. Each row and colum n corresponds t o an ident ified node, and m at rix
entries correspond to connections between nodes.

3.1.5 Control Structure Testing
Described below are some of the variations of Control Structure Testing.

3.1.5.1 Condition Testing
Condit ion t est ing is a t est case design m et hod t hat exercises t he logical
conditions contained in a program module.

3.1.5.2 Data Flow Testing
The dat a flow t est ing m et hod select s t est pat hs of a program according t o t he
locations of definitions and uses of variables in the program.


3.1.6 Loop Testing
Loop Test ing is a whit e box t est ing t echnique t hat focuses exclusively on t he validit y
of loop const ruct s. Four classes of loops can be defined: Sim ple loops, Concat enat ed
loops, nested loops, and unstructured loops.

3.1.6.1 Simple Loops
The following set s of t est s can be applied t o sim ple loops, where ‘n’ is t he
maximum number of allowable passes through the loop.
1. Skip the loop entirely.
2. Only one pass through the loop.
3. Two passes through the loop.
4. ‘m’ passes through the loop where m<n.
5. n- 1, n, n+1 passes through the loop.

3.1.6.2 Nested Loops
I f we ext end t he t est approach for sim ple loops t o nest ed loops, t he num ber of
possible tests would grow geometrically as the level of nesting increases.
1. Start at the innermost loop. Set all other loops to minimum values.
2. Conduct sim ple loop t est s for t he innerm ost loop while holding t he out er loops
at t heir m inim um it erat ion param et er values. Add ot her t est s for out - of- range or
exclude values.
3. Work out ward, conduct ing t est s for t he next loop, but keeping all ot her out er
loops at minimum values and other nested loops to “typical” values.
4. Continue until all loops have been tested.

3.1.6.3 Concatenated Loops
Concat enat ed loops can be t est ed using t he approach defined for sim ple loops, if
each of t he loops is independent of t he ot her. However, if t wo loops are
concat enat ed and t he loop count er for loop 1 is used as t he init ial value for loop
2, then the loops are not independent.

3.1.6.4 Unstructured Loops
Whenever possible, t his class of loops should be redesigned t o reflect t he use of
the structured programming constructs.

3.2 Black Box Testing
Black box t est ing, also known as behavioral t est ing focuses on t he funct ional
requirem ent s of t he soft ware. All t he funct ional requirem ent s of t he program will be
used to derive sets of input conditions for testing.

Black Box Testing Types
The following are the most famous/frequently used Black Box Testing Types.

3.2.1 Graph Based Testing Methods
Soft ware t est ing begins by creat ing a graph of im port ant obj ect s and t heir
relationships and t hen devising a series of t est s t hat will cover t he graph so
that each objects and their relationships and then devising a series of tests that
will cover t he graph so t hat each obj ect and relat ionship is exercised and error
are uncovered.

3.2.2 Equivalence Partitioning
Equivalence part it ioning is a black box t est ing m et hod t hat divides t he input
domain of a program into classes of data from which test cases can be derived.
EP can be defined according to the following guidelines:

1. I f an input condit ion specifies a range, one valid and one t wo invalid classes
are defined.
2. I f an input condit ion requires a specific value, one valid and t wo invalid
equivalence classes are defined.
3. I f an input condit ion specifies a m em ber of a set , one valid and one invalid
equivalence class are defined.
4. If an input condition is Boolean, one valid and one invalid class are defined.

3.2.3 Boundary Value Analysis
BVA is a t est case design t echnique t hat com plem ent s equivalence part it ioning.
Rat her t han select ing any elem ent of an equivalence class, BVA leads t o t he
select ion of t est cases at t he “ edges” of t he class. Rat her t han focusing solely
on input conditions, BVA derives test cases from the output domain as well.
Guidelines for BVA are sim ilar in m any respect s t o t hose provided for
equivalence partitioning.

3.2.4 Comparison Testing
Sit uat ions where independent versions of soft ware be developed for crit ical
applicat ions, even when only a single version will be used in t he delivered
com put er based syst em . These independent versions from t he basis of a black
box testing technique called Comparison testing or back- to- back testing.

3.2.5 Orthogonal Array Testing
The orthogonal array testing method is particularly useful in finding errors
associated with region faults – an error category associated with faulty logic
within a software component.

3.3 Scenario Based Testing (SBT)
Dr.Cem Kaner in “ A Pat t ern for Scenario Test ing” has explained scenario Based
Testing in great detail that can be found at www.testing.com.

What is Scenario Based Test ing and How/ Where is it useful is an int erest ing
question. I shall explain in brief the above two mentioned points.

Scenario Based Test ing is cat egorized under Black Box Test s and are m ost helpful
when t he t est ing is concent rat ed on t he Business logic and funct ional behavior of t he
applicat ion. Adopt ing SBT is effect ive when t est ing com plex applicat ions. Now, every
applicat ion is com plex, t hen it ’s t he t eam s call as t o im plem ent SBT or not . I would
personally suggest using SBT when t he funct ionalit y t o t est includes various feat ures
and funct ions. A best exam ple would be while t est ing banking applicat ion. As
banking applicat ions require ut m ost care while t est ing, handling various funct ions in
a single scenario would result in effective results.
A sam ple t ransact ion ( scenario) can be, a cust om er logging int o t he applicat ion,
checking his balance, t ransferring am ount t o anot her account , paying his bills,
checking his balance again and logging out.

In brief, use Scenario Based Tests when:
1. Testing complex applications.
2. Testing Business functionality.

When designing scenarios, keep in mind:
1. The scenario should be close to the real life scenario.
2. Scenarios should be realistic.
3. Scenarios should be traceable to any/combination of functionality.
4. Scenarios should be supported by sufficient data.

3.4 Exploratory Testing
Explorat ory Test s are cat egorized under Black Box Test s and are aim ed at t est ing in
conditions when sufficient time is not available for testing or proper documentation is
not available.

Exploratory testing is ‘Testing while Exploring’. When you have no idea of how the
application works, exploring the application with the intent of finding errors can be
termed as Exploratory Testing.

Performing Exploratory Testing
This is one big question for many people. The following can be used to perform
Exploratory Testing:
• Learn the Application.
• Learn the Business for which the application is addressed.
• Learn the technology to the maximum extent on which the application has
been designed.
• Learn how to test.
• Plan and Design tests as per the learning.

4.0 Structural System Testing Techniques

The following are the structural system testing techniques.

Technique Description Example
Stress Determine system performance Sufficient disk space
with expected volumes. allocated.
Execution System achieves desired level of Transaction turnaround
proficiency. time adequate.
Recovery System can be returned to an Evaluate adequacy of
operational status after a failure. backup data.
Operations System can be executed in a Determine systems can
normal operational status. run using document.
Compliance System is developed in accordance Standards follow.
with standards and procedures.
Security System is protected in accordance Access denied.
with importance to organization.

5.0 Functional System Testing Techniques

The following are the functional system testing techniques.

Technique Description Example
Requirements System performs as specified. Prove system
requirements.
Regression Verifies that anything unchanged Unchanged system
still performs correctly. segments function.
Error Handling Errors can be prevented or Error introduced into the
detected and then corrected. test.
Manual Support The people- computer interaction Manual procedures
works. developed.
Intersystems. Data is correctly passed from Intersystem parameters
system to system. changed.
Control Controls reduce system risk to an File reconciliation
acceptable level. procedures work.

Parallel Old systems and new system are Old and new system can
run and the results compared to reconcile.
detect unplanned differences.

4.0 Testing Phases

Requirement Study Requirement Checklist

Software Requirement
Specification

Software Requirement Functional Specification
Specification Checklist

Functional Specification
Document

Functional Specification Architecture Design
Document

Architecture Design Detailed Design Document

Coding

Functional Specification Unit Test Case Documents
Document

Unit Test Case Document
Design Document
System Test Case
Document
Document Integration Test Case
Document

Unit/Integration/System Regression Test Case
Test Case Documents Document

Document Performance Test Cases
and Scenarios
Performance Criteria

Software Requirement
Specification

Regression Test Case User Acceptance Test Case
Document Documents/Scenarios

Performance Test Cases
and Scenarios


4.2 Unit Testing

Goal of Unit t est ing is t o uncover defect s using form al t echniques like Boundary
Value Analysis ( BVA) , Equivalence Part it ioning, and Error Guessing. Defect s and
deviat ions in Dat e form at s, Special requirem ent s in input condit ions ( for exam ple
Text box where only num eric or alphabet s should be ent ered) , select ion based on
Com bo Box’s, List Box’s, Opt ion but t ons, Check Box’s would be ident ified during t he
Unit Testing phase.

4.3 Integration Testing

I nt egrat ion t est ing is a syst em at ic t echnique for const ruct ing t he program st ruct ure
while at t he sam e t im e conduct ing t est s t o uncover errors associat ed wit h
int erfacing. The obj ect ive is t o t ake unit t est ed com ponent s and build a program
structure that has been dictated by design.
Usually, the following methods of Integration testing are followed:
1. Top- down Integration approach.
2. Bottom- up Integration approach.

4.3.1 Top- down Integration
Top- down int egrat ion t est ing is an increm ent al approach t o const ruct ion of program
st ruct ure. Modules are int egrat ed by m oving downward t hrough t he cont rol
hierarchy, beginning wit h t he m ain cont rol m odule. Modules subordinat e t o t he m ain
cont rol m odule are incorporat ed int o t he st ruct ure in eit her a dept h- first or breadt h-
first manner.

1. The Integration process is performed in a series of five steps:
2. The main control module is used as a test driver and stubs are substituted for
all components directly subordinate to the main control module.
3. Depending on t he int egrat ion approach select ed subordinat e st ubs are
replaced one at a time with actual components.
4. Tests are conducted as each component is integrated.
5. On com plet ion of each set of t est s, anot her st ub is replaced wit h t he real
component.
6. Regression t est ing m ay be conduct ed t o ensure t hat new errors have not
been introduced.

4.3.2 Bottom- up Integration
Button- up int egrat ion t est ing begins const ruct ion and t est ing wit h at om ic m odules
(i.e. components at the lowest levels in the program structure). Because components
are int egrat ed from t he but t on up, processing required for com ponent s subordinat e
to a given level is always available and the need for stubs is eliminated.

1. A Bot t om - up int egrat ion st rat egy m ay be im plem ent ed wit h t he following
steps:
2. Low level com ponent s are com bined int o clust ers t hat perform a specific
software sub function.
3. A driver is written to coordinate test case input and output.
4. The cluster is tested.
5. Drivers are rem oved and clust ers are com bined m oving upward in t he
program structure.


4.4 Smoke Testing

“Smoke testing might be a characterized as a rolling integration strategy”.
Sm oke t est ing is an int egrat ion t est ing approach t hat is com m only used when
“shrink- wrapped” soft ware product s are being developed. I t is designed as a pacing
m echanism for t im e- critical projects, allowing the software team to assess its project
on a frequent basis.
The sm oke t est should exercise t he ent ire syst em from end t o end. Sm oke t est ing
provides benefits such as:
1) Integration risk is minimized.
2) The quality of the end- product is improved.
3) Error diagnosis and correction are simplified.
4) Progress is easier to asses.

4.5 System Testing

Syst em t est ing is a series of different t est s whose prim ary purpose is t o fully
exercise t he com put er based syst em . Alt hough each t est has a different purpose, all
work t o verify t hat syst em elem ent s have been properly int egrat ed and perform
allocated functions.
The following tests can be categorized under System testing:
1. Recovery Testing.
2. Security Testing.
3. Stress Testing.
4. Performance Testing.

4.5.1. Recovery Testing
Recovery t est ing is a syst em t est t hat focuses t he soft ware t o fall in a variet y of
ways and verifies t hat recovery is properly perform ed. I f recovery is aut om at ic,
reinit ializat ion, checkpoint ing m echanism s, dat a recovery and rest art are evaluat ed
for correct ness. I f recovery requires hum an int ervent ion, t he m ean- time- to- repair
(MTTR) is evaluated to determine whether it is within acceptable limits.

4.5.2. Security Testing
Securit y t est ing at t em pt s t o verify t hat prot ect ion m echanism s built int o a syst em
will, in fact , prot ect it from im proper penet rat ion. During Securit y t est ing, password
cracking, unaut horized ent ry int o t he soft ware, net work securit y are all t aken int o
consideration.

4.5.3. Stress Testing
St ress t est ing execut es a syst em in a m anner t hat dem ands resources in abnorm al
quant it y, frequency, or volum e. The following t ypes of t est s m ay be conduct ed
during stress testing;
• Special t est s m ay be designed t hat generat e t en int errupt s per second,
when one or two is the average rate.
• I nput dat a rat es m ay be increases by an order of m agnit ude t o det ermine
how input functions will respond.
• Test Cases that require maximum memory or other resources.
• Test Cases that may cause excessive hunting for disk- resident data.
• Test Cases that my cause thrashing in a virtual operating system.

4.5.4. Performance Testing
Perform ance t est s are coupled wit h st ress t est ing and usually require bot h hardware
and software instrumentation.


4.5.5. Regression Testing
Regression testing is the re- execution of some subset of tests that have already been
conducted to ensure that changes have not propagated unintended side affects.
Regression may be conducted manually, by re- executing a subset of al test cases or
using automated capture/playback tools.
The Regression test suit contains three different classes of test cases:
• A representative sample of tests that will exercise all software functions.
• Additional tests that focus on software functions that are likely to be
affected by the change.
• Tests that focus on the software components that have been changed.

4.6 Alpha Testing
The Alpha testing is conducted at the developer sites and in a controlled environment
by the end- user of the software.

4.7 User Acceptance Testing
User Accept ance t est ing occurs j ust before t he soft ware is released t o t he cust om er.
The end- users along with the developers perform the User Acceptance Testing with a
certain set of test cases and typical scenarios.

4.8 Beta Testing
The Bet a t est ing is conduct ed at one or m ore cust om er sit es by t he end- user of t he
soft ware. The bet a t est is a live applicat ion of t he soft ware in an environm ent t hat
cannot be controlled by the developer.

5.0 Metrics
Met rics are t he m ost im port ant responsibilit y of t he Test Team . Met rics allow for
deeper underst anding of t he perform ance of t he applicat ion and it s behavior. The
fine t uning of t he applicat ion can be enhanced only wit h m et rics. I n a t ypical QA
process, there are many metrics which provide information.
The following can be regarded as the fundamental metric:
IEEE Std 982.2 - 1988 defines a Functional or Test Coverage Metric. It can be used
to measure test coverage prior to software delivery. It provide a measure of the
percentage of the software tested at any point during testing.
It is calculated as follows:
Function Test Coverage = FE/FT
Where
FE is the number of test requirements that are covered by test cases that were
executed against the software
FT is the total number of test requirements

Software Release Metrics
The software is ready for release when:
1. It has been tested with a test suite that provides 100% functional coverage, 80%
branch coverage, and 100% procedure coverage.
2. There are no level 1 or 2 severity defects.
3. The defect finding rate is less than 40 new defects per 1000 hours of testing
4. The software reaches 1000 hours of operation
5. Stress testing, configuration testing, installation testing, Naïve user testing,
usability testing, and sanity testing have been completed


IEEE Software Maturity Metric
IEEE Std 982.2 - 1988 defines a Software Maturity Index that can be used to
determine the readiness for release of a software system. This index is especially
useful for assessing release readiness when changes, additions, or deletions are
made to existing software systems. It also provides an historical index of the impact
of changes. It is calculated as follows:
SMI = Mt - ( Fa + Fc + Fd)/Mt
Where
SMI is the Software Maturity Index value
Mt is the number of software functions/modules in the current release
Fc is the number of functions/modules that contain changes from the previous
release
Fa is the number of functions/modules that contain additions to the previous release
Fd is the number of functions/modules that are deleted from the previous release

Reliability Metrics
Perry offers the following equation for calculating reliability.
Reliability = 1 - Number of errors (actual or predicted)/Total number of
lines of executable code
This reliability value is calculated for the number of errors during a specified time
interval.
Three other metrics can be calculated during extended testing or after the system is
in production. They are:
MTTFF (Mean Time to First Failure)
MTTFF = The number of time intervals the system is operable until its first failure
MTBF (Mean Time Between Failures)
MTBF = Sum of the time intervals the system is operable
Number of failures for the time period
MTTR (Mean Time To Repair)
MTTR = sum of the time intervals required to repair the system
The number of repairs during the time period


6.0 Test Models
There are various models of Software Testing. Here in this framework I would
explain the three most commonly used models:

1. The ‘V’ Model.
2. The ‘W’ Model.
3. The Butterfly Model

6.1 The ‘V’ Model
The following diagram depicts the ‘V’ Model

Requirements Acceptance Tests

System Tests
Specification

Integration Tests
Architecture

Unit Tests
Detailed Design

Coding
The diagram is self- explanatory. For an easy understanding, look at the following
table:
SDLC Phase Test Phase
1. Requirements 1. Build Test Strategy.
2. Plan for Testing.
3. Acceptance Test Scenarios
Identification.
2. Specification 1. System Test Case Generation.
3. Architecture 1. Integration Test Case Generation.
4. Detailed Design 1. Unit Test Case Generation


6.2 The ‘W’ Model
The following diagram depicts the ‘W’ model:

Regression Requirements
Requirements
Round 3 Review
Performance
Testing

Regression
Specification Round 2 Specification System
Review Testing

Architecture Regression Architecture Integration
Round 1 Review Testing

Detailed Design Unit
Design
Testing
Review

Code Code
Walkthrough

The ‘W’ model depicts that the Testing starts from day one of the initiation of the
project and continues till the end. The following table will illustrate the phases of
activities that happen in the ‘W’ model:

SDLC Phase The first ‘V’ The second ‘V’
1. Requirements 1. Requirements Review 1. Build Test Strategy.
2. Plan for Testing.
3. Acceptance (Beta) Test Scenario
Identification.
2. Specification 2. Specification Review 1. System Test Case Generation.
3. Architecture 3. Architecture Review 1. Integration Test Case Generation.
4. Detailed Design 4. Detailed Design Review 1. Unit Test Case Generation.
5. Code 5. Code Walkthrough 1. Execute Unit Tests
1. Execute Integration Tests.
1. Regression Round 1.
1. Execute System Tests.
1. Regression Round 2.
1. Performance Tests
1. Regression Round 3
1. Performance/Beta Tests


In the second ‘V’, I have mentioned Acceptance/Beta Test Scenario Identification.
This is because, the customer might want to design the Acceptance Tests. In this
case as the development team executes the Beta Tests at the client place, the same
team can identify the Scenarios.

Regression Rounds are performed at regular intervals to check whether the defects,
which have been raised and fixed, are re- tested.

6.3 The Butterfly Model

The t est ing act ivit ies for t est ing soft ware product s are preferable t o follow t he
Butterfly Model. The following picture depicts the test methodology.

Test Design Test Analysis
Test Execution

Fig: Butterfly Model

I n t he Butterfly m odel of Test Developm ent , t he left wing of t he but t erfly depict s
the Te st An a lysis. The right wing depict s t he Te st D e sign , and finally t he body of
t he but t erfly depict s t he Te st Ex e cu t ion . How t his exact ly happens is described
below.

Test Analysis

Analysis is t he key fact or which drives in any planning. During t he analysis, t he
analyst understands the following:
• Verify t hat each requirem ent is t agged in a m anner t hat allows correlat ion of t he
tests for that requirement to the requirement itself. (Establish Test Traceability)
• Verify traceability of the software requirements to system requirements.
• Inspect for contradictory requirements.
• Inspect for ambiguous requirements.
• Inspect for missing requirements.
• Check t o m ake sure t hat each requirem ent , as well as t he specificat ion as a
whole, is understandable.
• I dent ify one or m ore m easurem ent , dem onst rat ion, or analysis m et hod t hat m ay
be used to verify the requirement’s implementation (during formal testing).
• Creat e a t est “ sket ch” t hat includes t he t ent at ive approach and indicat es t he
test’s objectives.
During Test Analysis t he required docum ent s will be carefully st udied by t he Test
Personnel, and the final Analysis Report is documented.
The following documents would be usually referred:

1. Software Requirements Specification.
2. Functional Specification.
3. Architecture Document.


4. Use Case Documents.

The An a lysis Re por t would consist of t he underst anding of t he applicat ion, t he
funct ional flow of t he applicat ion, num ber of m odules involved and t he effect ive Test
Time.

Test Design
The right wing of t he but t erfly represent s t he act of designing and im plem ent ing t he
t est cases needed t o verify t he design art ifact as replicat ed in t he im plem ent at ion.
Like test analysis, it is a relatively large piece of work. Unlike test analysis, however,
t he focus of t est design is not t o assim ilat e inform at ion creat ed by ot hers, but rat her
t o im plem ent procedures, t echniques, and dat a set s t hat achieve t he t est ’s
objective(s).
The out put s of t he t est analysis phase are t he foundat ion for t est design. Each
requirem ent or design const ruct has had at least one t echnique ( a m easurem ent ,
dem onst rat ion, or analysis) ident ified during t est analysis t hat will validat e or verify
that requirement. The tester must now implement the intended technique.
Soft ware t est design, as a discipline, is an exercise in t he prevent ion, det ect ion, and
elim inat ion of bugs in soft ware. Prevent ing bugs is t he prim ary goal of soft ware
t est ing. Diligent and com pet ent t est design prevent s bugs from ever reaching t he
im plem ent at ion st age. Test design, wit h it s at t endant t est analysis foundat ion, is
t herefore t he prem iere weapon in t he arsenal of developers and t est ers for lim it ing
the cost associated with finding and fixing bugs.
During Test Design, basing on t he Analysis Report t he t est personnel would develop
the following:

1. Test Plan.
2. Test Approach.
3. Test Case documents.
4. Performance Test Parameters.
5. Performance Test Plan.

Test Execution

Any test case should adhere to the following principals:
1. Accurate – tests what the description says it will test.
2. Economical – has only the steps needed for its purpose.
3. Repeatable – tests should be consistent, no matter who/when it is executed.
4. Appropriate – should be apt for the situation.
5. Traceable – the functionality of the test case should be easily found.

During t he Test Execut ion phase, keeping t he Proj ect and t he Test schedule, t he t est
cases designed would be execut ed. The following docum ent s will be handled during
the test execution phase:
1. Test Execution Reports.
2. Daily/Weekly/monthly Defect Reports.
3. Person wise defect reports.

After the Test Execution phase, the following documents would be signed off.

1. Project Closure Document.
2. Reliability Analysis Report.
3. Stability Analysis Report.
4. Performance Analysis Report.
5. Project Metrics.


7.0 Defect Tracking Process

The Defect Tracking process should answer the following questions:
1. When is the defect found?
2. Who raised the defect?
3. Is the defect reported properly?
4. Is the defect assigned to the appropriate developer?
5. When was the defect fixed?
6. Is the defect re- tested?
7. Is the defect closed?

The defect tracking process has to be handled carefully and managed efficiently.

The following figure illustrates the defect tracking process:

The Tester/Developer
finds the Bug.

Reports the Defect in
the Defect Tracking
Tool. Status “Open”

The concerned
Developer is informed

The Developer fixes
the Defect

The Developer If the Defect re-
changes the Status to occurs, the status
“Resolved” changes to “Re- Open”

The Tester Re- Tests
and changes Status to
“Closed”

Defect Classification

This sect ion defines a defect Severit y Scale fram ework for det erm ining defect
crit icalit y and t he associat ed defect Priorit y Levels t o be assigned t o errors found
software.


The defects can be classified as follows:

Classification Description
Critical There is s funct ionalit y block. The applicat ion is not able t o
proceed any further.
Major The applicat ion is not working as desired. There are variat ions in
the functionality.
Minor There is no failure report ed due t o t he defect , but cert ainly needs
to be rectified.
Cosmetic Defects in the User Interface or Navigation.
Suggestion Feature which can be added for betterment.

Priority Level of the Defect

The priorit y level describes t he t im e for resolut ion of t he defect . The priorit y level
would be classified as follows:

Classification Description
Immediate Resolve the defect with immediate effect.
At the Earliest Resolve the defect at the earliest, on priority at the second level.
Normal Resolve the defect.
Later Could be resolved at the later stages.

8.0 Test Process for a Project

I n t his sect ion, I would explain how t o go about planning your t est ing act ivit ies
effect ively and efficient ly. The process is explained in a t abular form at giving t he
phase of testing, activity and person responsible.

For t his, I assum e t hat t he proj ect has been ident ified and t he t est ing t eam consist s
of five personnel: Test Manager, Test Lead, Senior Test Engineer and 2 Test
Engineer’s.

SDLC Phase Testing Phase/Activity Personnel
1. Requirements 1. Study the requirements for Test Manager / Test Lead
Testability.
2. Design the Test Strategy.
3. Prepare the Test Plan.
4. Identify scenarios for
Acceptance/Beta Tests
2. Specification 1. Identify System Test Cases / Test Lead, Senior Test
Scenarios. Engineer, and Test Engineers.
2. Identify Performance Tests.
3. Architecture 1. Identify Integration Test Cases / Test Lead, Senior Test
Scenarios. Engineer, and Test Engineers.
2. Identify Performance Tests.
4. Detailed 1. Generate Unit Test Cases Test Engineers.
Design


9.0 Deliverables
The Deliverables from the Test team would include the following:

1. Test Strategy.
2. Test Plan.
3. Test Case Documents.
4. Defect Reports.
5. Status Reports (Daily/weekly/Monthly).
6. Test Scripts (if any).
7. Metric Reports.
8. Product Sign off Document.


software-testing-framework 3

More Related Content

Similar to software-testing-framework 3

software-testing-framework 3