What Is Software Quality Attribute

by Anna Khrupa on May 27, 2022

The concept of quality takes a significant place in software development. No matter what kind of project you have, the main focus is on quality, the desirable properties and features of a product. To understand whether the software solution satisfies the requirements or not, quality has to be measured by a degree of quality attribute combinations. So, what is an attribute of quality in software development?

Quality attributes, or technical requirements, are measurable and testable properties of the system and the way they satisfy the needs of a user. It is a set of features or properties to measure the performance and characterize how useful the software in a specific environment is.

The Insight into Software Quality Attributes and Properties

Software quality attributes can be divided into properties visible to a development team and client or a development team only. For example, such qualities as reliability and usability are directly experienced by a client. While maintainability is a quality attribute of a software that can be fully evaluated by a development organization exclusively. All of them measure product performance or quality assurance and control.

List of Quality Attributes in Software

The following attributes are common for most applications, though every company identifies a set of the right criteria by itself to plan the resources efficiently.

Some of the major attributes to identify the level of software development quality are:

• Availability;
• Correctness;
• Interoperability;
• Modifiability;
• Maintainability;
• Performance;
• Usability;
• Reusability;
• Reliability;
• Security;
• Testability.

The first attribute of software quality is availability. It is the percentage of time a system should be up and running with a focus on critical operational capabilities concerns. Availability indicates whether the system can do those tasks it is assigned to. Does it provide the service that it was created for? Availability can be perceived as a part of reliability, which is the ability to operate under different conditions. 

Correctness defines the ability of the system to perform tasks as defined by its specification. If the program is consistent with its specification, it is considered to be 100% correct. The system is either correct or not correct at all. Correctness has no middle position. It is an all-or-nothing attribute.

Interoperability measures how well the system interacts with other systems. Or, how easy is it to move your system to another platform? How well can two or more systems exchange and interpret data via interfaces? The software solution should be able to run on numerous platforms.

The next one in the quality attribute definition is modifiability. It represents the property that measures how easy it is to make a change to the system. How much can be modified? How many changes can be made? Software systems are constantly changing and evolving, being modified more than once after development. It can be a costly process if the software is not initially prepared for future changes to be incorporated. Modifiability plays an important role in cost maintenance during a development lifecycle.

Maintainability displays how costly it is to keep the system running without breaking down. This property demonstrates whether the changes can be adapted cost-effectively or not. Can they be maintained easily? The program should be written in a way to be ready to meet the changing needs of a user. Can the product be changed as required by users? Is the code easy to read and understand? How difficult will it be to add new features in the future?

System speed and efficiency are measured with a performance attribute. How much data and memory can the system handle? Can it respond to the required task within a set time frame? How quickly and effortlessly can a certain task be done? The response time should always be as expected. Performance attribute concerns speed, availability, efficiency, and response/recovery time. If the performance is low, the system cannot be used in real-time programs.

Usability quality is an attribute of navigation. It measures the user experience while interacting with a system. How long does it take for the system to execute a task? How easy is it for a user to learn to do a task? How many buttons should a person click on to do a certain task? How well can the system meet the user’s requirements? How intuitive and accessible is it? Simple navigation is key to a user-friendly program. People expect to be able to use a website or an application without previous training.

Reusability means different code library classes should be created in a way to be easily used in different program modules. In other words, components in one system can be used as components in another system without a change. It is an important attribute of quality to reduce development costs and time.

Reliability is about how well the system operates over a period of time. The program should work smoothly under different conditions in different environments.

Security displays how the system manages malicious or unauthorized access or modification, which can destroy it and compromise the legitimate user’s experience. Security is measured by the ability of the program to operate without risk of harm to users, the software environment, and resources. The system should guarantee users or data senders that data have been delivered and received without being exposed and that the system or data itself is not corrupted.

And last but not least, what is a quality attribute to measure the easiness of the system during a testing process? Testability handles how fast the system can be tested. How fast can a test for a specific feature be created? To what degree can the testing process be automated? How hard is it to check the program? Software products with a low testability level are considered less trustworthy and more expensive to maintain and update. Improved testability has a direct positive impact on making the testing process efficient and cost-effective.

Quality attributes and properties play a huge role in software system design in general. They affect the ability to meet user requirements and the software architecture, which is more complex and much more of a higher quality than before.

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