Introduction to software testing and quality assurance

UNIT-I
Introduction to Software Testing and
Quality Assurance
Dr. Dhanraj. S. Jadhav
Department of Computer Engg., JSPM’s RSCOE, Pune-33
Subject : STQA

COURSE OBJECTIVE
Introduce basic concepts of software testing
• To learn concept of Software Testing.
• To understand the levels of testing in the user
environment.
• To understand white box, block box, object
oriented, web based and cloud testing
• To learn and understand the importance software
quality and assurance.
• To understand in details automation testing and
tools for automation testing
Unit-1-Introduction

COURSE OUTCOMES
 Describe fundamental concepts in software testing such as manual testing,
automation testing and software quality assurance.
 Design and develop project test plan, design test cases, test data, and
conduct test operations.
 Apply various levels of testing software .
 Apply specialised testing environment.
 Apply and analyze automation tool.
 Apply and analyze effectiveness Software Quality Tools & Management
Unit-1-Introduction

INTRODUCTION
Introduction
Historical Perspective
Definition
Core Components
Quality View
Financial Aspect
Customer Suppliers and Process
Total Quality Management(TQM)
Quality Management Through Statistical Process Control
Cultural Changes
Continual Improvement Cycle
Quality In Different Areas
Benchmarking and Metrics
Problem Solving Techniques
Problem Solving Software Tools
Unit-1-Introduction

INTRODUCTION(Conti..)
Software Quality.
Constraints of Software Product.
Customer is a King.
Quality and Productivity Relationship.
Requirements of Products.
Organization Culture.
Software Development Process.
Types of Product.
Problematic areas of SDLC.
Software Quality Management.
Why Software has a defects?
Processes related to Software Quality.
Pillars of Quality Management System.
Important aspects of quality Management.
Unit-1-Introduction

INTRODUCTION
 Software Quality
Quality: The degree to which a component, system or process meets specified
requirements and/or user/customer needs and expectations.
Software Quality: The totality of functionality and features of a software product that bear
on its ability to satisfy stated or implied needs.
OR
SOFTWARE QUALITY is the degree of conformance to explicit or implicit requirements
and expectations.
KEYWORDS:
Explicit: clearly defined and documented
Implicit: not clearly defined and documented but indirectly suggested
Requirements: business/product/software requirements
Expectations: mainly end-user expectations
Unit-1-Introduction

INTRODUCTION(conti…)
Software testing is a process of executing a program
or application with the intent of finding the
software bugs.
It can also be stated as the process of validating
and verifying that a software program or
application or product: Meets the business and
technical requirements that guided it’s design and
development
Works as expected
Can be implemented with the same characteristic.
Unit-1-Introduction

INTRODUCTION(conti…)
The software system needs to be checked for its
intended behavior and direction of progress at
each development stage to avoid duplication of
efforts, time and cost overruns, and to assure
completion of the system within stipulated time.
System testing and quality assurance come to aid
for checking the system. It includes −
Product level quality (Testing)
Process level quality.
Unit-1-Introduction

TESTING
Testing is the process or activity that checks the functionality
and correctness of software according to specified user
requirements in order to improve the quality and reliability of
system. It is an expensive, time consuming, and critical
approach in system development which requires proper
planning of overall testing process.
Characteristics of System Testing
System testing begins at the module level and proceeds
towards the integration of the entire software system.
Different testing techniques are used at different times while
testing the system. It is conducted by the developer for small
projects and by independent testing groups for large projects.
Unit-1-Introduction

WHY IS SOFTWARE TESTING
NECESSARY?
Software Testing is necessary because we all make mistakes. Some of
those mistakes are unimportant, but some of them are expensive or
dangerous. We need to check everything and anything we produce
because things can always go wrong –
humans make mistakes all the time. Software testing is very important
because of the following reasons:
Software testing is really required to point out the defects and errors
that were made during the development phases.
It’s essential since it makes sure of the Customer’s reliability and their
satisfaction in the application.
It is very important to ensure the Quality of the product. Quality
product delivered to the customers helps in gaining their confidence.
(Know more about Software Quality)
Unit-1-Introduction

Conti..
Testing is necessary in order to provide the facilities to the customers like the
delivery of high quality product or software application which requires lower
maintenance cost and hence results into more accurate, consistent and reliable
results.
Testing is required for an effective performance of software application or
product.
It’s important to ensure that the application should not result into any failures
because it can be very expensive in the future or in the later stages of the
development.
It’s required to stay in the business.
Unit-1-Introduction

WHAT ARE SOFTWARE TESTING
OBJECTIVES AND PURPOSE?
Software Testing has different goals and objectives.The major
objectives of Software testing are as follows:
Finding defects which may get created by the programmer while
developing the software.
Gaining confidence in and providing information about the level of
quality.
To prevent defects.
To make sure that the end result meets the business and user
requirements.
To ensure that it satisfies the BRS that is Business Requirement
Specification and SRS that is System Requirement Specifications.
To gain the confidence of the customers by providing them a quality
product.
Unit-1-Introduction

STAGES OF SYSTEM
TESTING
Test Strategy
It is a statement that provides information about the
various levels, methods, tools, and techniques used for
testing the system.
It should satisfy all the needs of an organization.
Unit-1-Introduction

TEST PLAN
It provides a plan for testing the system and verifies that the system
under testing fulfils all the design and functional specifications. The
test plan provides the following information −
Objectives of each test phase
Approaches and tools used for testing
Responsibilities and time required for each testing activity
Availability of tools, facilities, and test libraries
Procedures and standards required for planning and conducting the
tests
Factors responsible for successful completion of testing process
Unit-1-Introduction

TEST CASE DESIGN
Test cases are used to uncover as many errors as possible in the
system.
A number of test cases are identified for each module of the system to
be tested.
Each test case will specify how the implementation of a particular
requirement or design decision is to be tested and the criteria for the
success of the test.
The test cases along with the test plan are documented as a part of a
system specification document or in a separate document called test
specification or test description.
Unit-1-Introduction

TEST PROCEDURES
It consists of the steps that should be followed to execute
each of the test cases. These procedures are specified in a
separate document called test procedure specification. This
document also specifies any special requirements and
formats for reporting the result of testing.
Test Result Documentation
Test result file contains brief information about the total
number of test cases executed, the number of errors, and
nature of errors. These results are then assessed against
criteria in the test specification to determine the overall
outcome of the test.
Unit-1-Introduction

HISTORICAL PERSPECTIVE
Unit-1-Introduction

DEFINATIONS OF QUALITY
Customer-Based Definition of Quality.
Quality must have fitness foe use and meet customer needs ,requirements
and help in achieving customer satisfaction and customer delight.
Manufacturing-Based Definition of Quality.
This approach gives conformance to requirements.
Product-Based Definition of Quality.
Product must have something that other similar products do not have
which help customer satisfy their needs in better way.
Value-Based Definition of Quality.
Customer must get value for his investment by buying product.
Transcendent Quality.
A product must have zero defects so that it does not prohibit normal
usage by the users.
Unit-1-Introduction

CORE COMPONENTS OF QUALITY
Quality is based on Customer satisfaction by
acquiring a product.
The organization must define quality parameters
before it can be achieved. The cycle of
measurement include,
Define , Measure, Monitor, Control, Measure.
Management Must Lead Organisation through
improvement efforts.
Continuous Process improvement is necessary.
Unit-1-Introduction

QUALITY VIEW(cont.…)
 Different views of Quality.
Transcendental view
User view
Manufacturing view
Product view
Value-based view
Unit-1-Introduction

• Transcendental view
– Quality is something that can be recognized through experience, but not
defined in some tractable form.
– A good quality object stands out, and it is easily recognized.
• User view
– Quality concerns the extent to which a product meets user needs and
expectations.
– Is a product fit for use?
– This view is highly personalized.
• A product is of good quality if it satisfies a large number of users.
• It is useful to identify the product attributes which the users consider to
be important.
– This view may encompass many subject elements, such as usability,
reliability, and efficiency
Unit-1-Introduction

• Manufacturing view
– This view has its genesis in the manufacturing industry – auto and
electronics.
– Key idea: Does a product satisfy the requirements?
• Any deviation from the requirements is seen as reducing the quality
of the product.
– The concept of process plays a key role.
– Products are manufactured “right the first time” so that the cost is reduced
• Development cost
• Maintenance cost
– Conformance to requirements leads to uniformity in products.
– Some argue that such uniformity does not guarantee quality.
– Product quality can be incrementally improved by improving the process.
Unit-1-Introduction

• Product view
– Hypothesis: If a product is manufactured with good internal properties, then it will
have good external properties.
– One can explore the causal relationship between internal properties and external
qualities.
– Example: Modularity enables testability.
• Value-based view
– This represents the merger of two concepts: excellence and worth.
– Quality is a measure of excellence, and value is a measure of worth.
– Central idea
• How much a customer is willing to pay for a certain level of quality.
• Quality is meaningless if a product does not make economic sense.
• The value-based view makes a trade-off between cost and quality.
Unit-1-Introduction

FINANCIALASPECT OF QUALITY
-Quality affects all aspects of the organization
-Quality has dramatic cost implications of:
 Quality control costs

Prevention costs

Appraisal costs
 Quality failure costs

Internal failure costs

External failure costs
Sales Price is defined as,
Sales Price=Cost of Manufacturing+
Cost of Quality + Profit
Unit-1-Introduction

CUSTOMER ,SUPPLIERS
AND PROCESSES
For any Organisation ,there are some suppliers supplying the inputs required and
some customers who will be buying the output produced.
Supplier and customers may be internal or external to the organization.
External supplier provide input to the organization and external customers receive
the output of the organization.
Suppliers may be customer for some organization and external customers receives
the output of the organization.
Internal Customer:
Internal customer are the functions and projects serviced and supported by
some other functions / projects. System administration may have projects as their
customer while purchasing may have system administration as their customer.
External Customer:
External customer are the external people to the organization who will be
paying for the services offered by the organization.
Unit-1-Introduction

TOTAL QUALITY
MANAGEMENT(TQM)
Total Quality Management (TQM) efforts to position a company for greater
customer satisfaction, profitability and competitiveness.
TQM principle intends to view internal and external customers as well as internal
and external suppliers for each process and project and entire organization as whole
• Meeting Our Customer’s Requirements
• Doing Things Right the First Time; Freedom from Failure (Defects)
• Consistency (Reduction in Variation)
• Continuous Improvement
• Quality in Everything We Do
Unit-1-Introduction

TOTAL QUALITY
MANAGEMENT(TQM) (Conti..)
 Focus on Customer
 Identify and meet customer needs
 Stay tuned to changing needs, e.g. fashion styles
 Continuous Improvement
 Continuous learning and problem solving, e.g. Kaizen, 6 sigma
 Plan-D-Study-Act (PDSA)
 Benchmarking
 Employee Empowerment
 Empower all employees; external and internal customers
 Team Approach

Teams formed around processes – 8 to 10 people

Meet weekly to analyze and solve problems
 Use of Quality Tools
 Ongoing training on analysis, assessment, and correction, & implementation tools
 Studying practices at “best in class” companies
Unit-1-Introduction

QUALITY MANAGEMENT
THROUGH STASTICAL PROCESS
CONTROL
Statistical process control is a collection of tools that when used together can
result in process stability and variance reduction
Statistical Process Control (SPC) is an industry-standard methodology for
measuring and controlling quality during the manufacturing process.
Quality data in the form of Product or Process measurements are obtained in real-
time during manufacturing. This data is then plotted on a graph with pre-
determined control limits. Control limits are determined by the capability of the
process, whereas specification limits are determined by the client's needs.
Quality Planning at all level
Quality Planning at Organization level.
Quality Planning at Unit level.
Statistical Process Control
monitoring production process to detect and prevent poor quality
Sample
subset of items produced to use for inspection
Unit-1-Introduction

QUALITY MANAGEMENT
THROUGH CULTURAL CHANGES
Quality Management through cultural change defines quality improvements as
a cultural change driven by management. It involves
-Identifying areas in which quality can be improved depending upon process
capability measurements and organizational priorities.
-Identifying teams representing different functions and areas for quality
improvement can help in setting the change of culture.
-Setting measurable goals in each areas of an organization can help in
improving processes at all levels.
-Giving recognition to achievers of quality goals will boost their morale and set
positive competition among team leading to organizational improvements.
Creating a quality culture within an organization is increasingly recognized as
one of the primary conditions for the successful implementation of Total
Quality Management
Unit-1-Introduction

CONTINUAL IMPROVEMENT
CYCLE(Conti)
Continuous improvement is an ongoing effort to improve products, services or
processes. These efforts can seek “incremental” improvement over time or
“breakthrough” improvement all at once.
Among the most widely used tools for continuous improvement is a four-step
quality model—the plan-do-check-act (PDCA) cycle, also known as Deming
Cycle or Shewhart Cycle:
Plan: Identify an opportunity and plan for change.
Do: Implement the change on a small scale.
Check: Use data to analyze the results of the change and determine whether it
made a difference.
Act: If the change was successful, implement it on a wider scale and
continuously assess your results. If the change did not work, begin the cycle
again.
Unit-1-Introduction

CONTINUAL IMPROVEMENT
CYCLE
Fig.PDCA Cycle
Unit-1-Introduction

QUALITY IN DIFFERENT
AREAS
Quality attributes of various products in different areas..
Different domains need different quality factors. They may be derived from
customers/users of the domains. Some examples of some domains showing
customer expectations in terms of quality of various products.
Products and expected attributes
Products/Service Category Expected Attributes
Airline Industry On time arrival/departure, low cost
service, comfortable journey etc.
Healthcare Industry Correct treatment, minimum wait
time ,safety and security .
Food Service Industry Good Product, good taste, fast
delivery, clean environment.
Military Services Rapid deployment, Security
Automotive Industry Clear communication, faster acess,
cheaper service
Unit-1-Introduction

BENCHMARKING AND
METRICS
Benchmarking:-
It is important concept in Quality Function Deployment (QFD).
It is concept of qualitative /quantitative metrics or measurable variables which
can used to access product quality on several scales against benchmarks..
Benchmarking include price of product paid by customer, time required to
acquired to acquire it, customer satisfaction, defects, attributes and features of
products.
Benchmarking means to measure the best practices of leading businesses, and
learn and adapt them for use in your business.
Metrics:-
They are defined for collecting information about the products capabilities,
process variability and outcome of the process in terms of attributes of the
product.
It is relative measurement of some parameters of a product which are related
to the product and processes used to make it.
Unit-1-Introduction

PROBLEM SOLVING TECHNIQES
Techniques indicate more about a process used in measurement , analysis and decision
making during problem solving.
Improving quality of products and services offered to customers requires methods and
techniques of solving problems associated with development and processes used during
their lifecycle.
An organization must use metrics approach of process improvement because it needs to
make quantitative measurements.
These measurements can be accomplished by both qualitative and quantitative methods but
problem definition becomes easier when we put some measures.
Qualitative problem solving refers to understanding a problem solution using only
qualitative indexes such as high , medium ,low etc. depending on the something is
improving from present status and so forth.
Quantitative problem solving requires specification of exact measures of exact measures in
numerical terms such as the cost of the 32.5% during last quarter or time required to one
product is reduced by 32 minutes.
It must follow define, measure,monitor,control and improve cycle.
Unit-1-Introduction

PROBLEM SOLVING
SOFTWARE TOOLS
Tools are an organizations analytical asset that assist in understanding a problem
through data and try to indicate possible solutions.
Quality tools applied for solving problems face by projects and functional terms
while improving quality in organization.
Tools may be hardware/software and physical/logical tools.
Advantages of Using Software Tools for analysis and decision making
-Accuracy and speed of the tools is much higher compared to performing all
transactions and calculations manually.
-Decision support offered of the tool is independent of personal skills and there is
least variation from instance to instance.
-Tools can be integrated with other systems to provide a systematic and highly
integrated means of solving problems.
Disadvantages of Using Computer Tools for Analysis and Decision Making
-Tools may mean more cost and time to learn and implement.
Unit-1-Introduction

SOFTWARE QUALITY
 Software Quality Views
The degree to which a system, component, or process meets specified
requirements.
Quality is fitness for use.
Conformance to specification.
Transparency of service delivery
Achieving desired results
Continuous Improvement
Competitive advantage
Added value for society Best value for price
Cost effectiveness
Performance measurement
Satisfaction of stakeholders
Doing the right things
Doing things right
Doing the right things right
Unit-1-Introduction

CONSTRAINTS OD SOFTWARE
PRODUCT QUALITY ASSESSMENT
Requirement specification are made by business analyst and system analyst.
Tester may or may not have direct access to the customer and may get information
though requirement statements, queries answered etc. either from customer or
business analyst. There are few limitation of product quality assessment in this.
Software is virtual in nature. Software products can not be touched or heard.
There is huge communication gap between users of software and
developers/testers of the product.
Software product is unique in nature. Similarities between any two products
are superficial ones.
All aspects of software cannot be tested fully as member of permutations and
combinations for testing all possibilities tend to infinity.
A software program in the same way every time when it is executing some
instruction.
Unit-1-Introduction

QUALITY TOOLS
Quality function deployment (QFD)
Taguchi techniques
Pareto charts
Process charts
Cause & effect diagrams
Statistical process control (SPC)

CUSTOMER IS A KING
External Customer - outside the organization (people who pay the bills.)
End-user customers
Manufacturer (OEM) for suppliers.
Internal Customer - people within your organization who receive your work
In many situations, producers have multiple customers and therefore find it useful
to identify “core customers”
A customer’s perception is their reality.
It’s easier to keep your customers happy than attract new ones.
Complaints spread like wildfire on the internet.
Without customers we don’t have a business.
Brands win or lose by how well they wow customer.
TQM’s Customer Approach
the customer defines quality.”
“the customer is always right.”
“the customer always comes first.”
“quality begins and ends with the customer.”
Unit-1-Introduction

QUALITY AND PRODUCTIVITY
RELATIONSHIP
Productivity is the relationship between a given amount of output and the
amount of input needed to produce it. Quality affects productivity.
Productivity is tool of measurement that determines the efficiency of the
organization in terms of the ratio of output produced with respect to inputs
used.
Quality must improve productivity by reducing wastage.
Improvement in quality directly leads to improved productivity.
Cost reduction is possible by improved quality.
Proper communication between management and employee is essential.
Quality improvement lead to cost reduction.
Employee involvement in quality improvement.
Unit-1-Introduction

REQUIREMENTS OF
PRODUCT
Stated/Implied Requirements: Functional and non functional requirements
stated by customer.
General/Specific Requirement: Requirements are generic in nature.
Present/Future Requirements: Present when application is used and future
for required after some time span.
Primary Requirements: Must /must not be requirements. Customer pay for
this
Secondary Requirements: Should/Should not be requirements.
Tertiary Requirements: Could/could not be requirements.
Unit-1-Introduction

ORGANIZATION CULTURE
Quality culture is set of group values that guide how improvements are made
to everyday working practices and consequent outputs.
An organization’s values can help individuals at all levels make better and
more responsible decisions relating issues of quality.
Following Features emerged as indicative of a quality culture
-Academic Ownership of quality.
-Quality culture is primarily about the behavior of stakeholders rather
than the operation of a quality.
-A quality culture places students as center.
Unit-1-Introduction
QUALITY
CONTROL
QUALITY
ASSURANCE
QUALITY
MANAGEMENT
Fig .Shift focus from quality control to quality management

SOFTWARE
DEVELPOMENT PRCOESS
Following Software Development Process Models are used:
Waterfall Development Approach/Model.
Iterative Development Approach/Model
Incremental Development Approach/Model
Spiral Development Approach/Model
Prototyping Development Approach/Model
Rapid Development Approach/Model
Agile Development Approach/Model
Unit-1-Introduction

TYPES OF PRODUCT
Life Affecting Products.
Product Affecting Huge Some of Money.
Products Which can be Tested only by Simulators
:Example Space Research
Other Products.
Unit-1-Introduction

Unit-1-Introduction
• CRITICALITY DEFINATIONS
• Problematic areas of SDLC
• Software Quality Management
• Why Software has defects
• Processes related to Software Quality

CRITICALITY DEFINATIONS
From User’s Perspective:
-Failure of product disrupts entire business.
-Products failure affects business.
From Developer's Perspective
-This classification defines the complexity of the system on the basis of
development capabilities required.
Unit-1-Introduction

PROBLEMSTIC AREAS OF
SDLC
Problems with requirement phase.
Requirements change very frequently.
Unique product is built in any time.
Product nature is intangible.
Inspection can be exhaustive.
Requirements are not easily communicated.
-Technical Requirements.
-Economical Requirements.
-Operational Requirements.
-System Requirements.
Unit-1-Introduction

SOFTWARE QUALLITY
MANAGEMNT
Quality management involves management of all inputs and processsing
defined so that the output from the process as per defined criteria.
It handles three levels of problems:
-Correction.
-Corrective Actions.
-Preventive Actions.
Unit-1-Introduction

QUALITY MANAGEMENT SYSTEM
STRUCTURE
1st
Tier-Quality policy
2nd
Tier-Quality objectives
3rd
Tier-Quality Manual

PILLARS OF QUALITY
MANAGEMENT SYSTEM
Quality processes/Quality Procedures/work
instructions
Guidelines and standards
Formats and Templates

IMPORTANT ASPECTS OF QUALITY
MANAGEMENT
Quality planning at organisation level
Quality planning at project level
Resource management
Work Environment
Customer Related Processes
Quality management system document and data control
Verification and validation
Software project management
Software configuration management
Software metrics and measurement
Software Quality Audits

Introduction to software testing and quality assurance

More Related Content

Similar to Introduction to software testing and quality assurance (20)

Recently uploaded (20)

Introduction to software testing and quality assurance