Page 183 - SOFTWARE TESTING & QUALITY ASSURANCE

Software Testing and Quality Assurance

In the year 2009 – 2010, Toyota Motors had recalled millions of its vehicles.
This is because most of the vehicles had experienced an increased acceleration.
This was due to incorrect placement of the driver’s front floor mat at the foot
pedal well. The wrong placement resulted in pedal entrapment when the
vehicle was in motion. However, on investigation, it was found that the
quality of the foot mat was low and this had caused the unintended
acceleration in the vehicle.

12.1 Definition of Quality

“Quality is the enduring process of building and sustaining relationships by assessing, anticipating, and
fulfilling stated and implied needs” Winder, Richard E. and Judd, Daniel K., 1996.
Quality can be defined as a state of being free from defects and deficiencies. It is achieved by adopting
strict and consistent adherence to measure and verify the set standards to attain uniformity in the
output which satisfies specific user requirements.
ISO defines quality as "the totality of features and characteristics of a product or service that bears its
ability to satisfy stated or implied needs”. It is the state of being free from defects and deficiencies by
adopting strict and consistent adherence to measure and verify the set standards in order to attain
uniformity in the output. This in turn satisfies specific user requirements.
To understand the meaning and importance of software quality in the software industry, we first need
to understand the activities related to quality such as software quality assurance and software quality
control.
Software Quality

When a software system or a process achieves a particular standard that satisfies the customer
expectations, then the system is supposed to have achieved ‘quality software’ standard.
While measuring the features of a software product, two factors, namely: the quality of design and the
quality of conformance are taken into consideration. Quality of design comprises a class of materials,
the tolerance capacity, and the work specifications of the item. The quality of design is said to be
fantastic when good class of materials are used to make the product. These materials are set to tolerate
rigid circumstances and to perform at tough levels. The quality of a product can be judged by looking at
the specifications.
When a product is set to execute its performance at high levels but performs really low, then it is
understood that the quality of the design is low. The quality of conformance provides the extent to
which the designed specifications are followed during the development of the product. This implies
that if the design specifications are set high, but are not followed, then this will affect the quality of the
product. Software quality is a mixture of factors that varies with the different software applications.
The factors that affect the software quality are categorized into two groups. They are:
1. The directly measured factors like errors, lines of code, and unit time.
2. The indirectly measured factors like usability or maintainability.
Measurements are considered for both directly and indirectly measured factors. We need to formulate
an empirical connection between the quality factors and the software quality itself, which signifies that
we understand the indirect factors that determine the software quality.

Following are the indirectly measured factors that affect the quality of software product:
1. Reliability: Reliability is the extent to which a program performs its proposed function with the
required accuracy.
2. Efficiency: Efficiency is the quantity of computing resources and code required by a program to
execute its function.
3. Integrity: Integrity identifies the extent of control in accessing the particular software product.

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