Introduction

Paper Overview

In recent times software development has become an immense piece of interest because it involves analytics, innovation and integration of data. All large organizations have legacy applications and systems, but they are leaving no stone unturned, to adopt and integrate their existing systems with the newer ones [1]. But in all this the main challenge for the software industries, still remains to find out adequate and useful testing techniques.

This paper concentrates on what have been different software development models, where does testing come in picture and analysis of different types of testing techniques in the lifecycle of product development. This paper highlights testing methodologies and upcoming newer methods of agile testing in software industry.

What is Software Quality?

It is a degree to which a system, component or process meets specified requirements [1].

• Verification- Activity to demonstrate the result of the next stage of development complies with specification in the previous stage [1].
• Validation- Activity to check whatever was required out of the product was achieved[1].

Types of Issues faced in Testing [1][2]:

Error	Fault	Defect	Failure
It is a discrepancy between computed, observed or measured value or condition to that of a true, specified or theoretically correct value or condition [1]	An abnormal condition that may cause a reduction in or loss of, the capability of a functional unit to perform a required function[1].	A flaw in a component or system that can cause the component or system to fail to perform its required function[1][2]	The termination of the ability of a functional unit to achieve a required function [1][2].
E.g.- Human error	E.g.-System downtime, login functionality fails.	E.g.- Login application does not have login button- HUGE DEFECT!!	E.g.- Airbag deployment failure.

Importance of Testing [31]

If any given product, commodity, application does not work according to the requirements, there is an extensive impact on any organization. Some of the major issues encountered are:

• Financial penalties, loss of money
• Loss of time- Transactions are taking huge amount of time to process in a retail store, which in turn can cause huge waiting lines, anxiety in staff and customers.
• Damage to business branding- Any failure or fault in the product, leads to dissatisfied customers, which impacts the branding of an organization. Customers loose their trust in the company, which results in loss of business and revenue.
• Injury or death- failure to launch an airbag in car in an accident, faulty flight control system, all can result in fatalities, which can impact lives at large.

According to National institute of standards and technology, below is the cost of fixing defects in SDLC phases.