Day by day we face tasks and problems, solving of which is impossible without a high-quality software. Even the most expensive equipment is nothing if it lacks a good one.

A well written program can give a new life even to the outdated device. It may take seemingly a useless thing to a new functional level. And it means making a commercial revolution in the world of innovative technologies.

What is qualitative software? If to delve deeply into the notion of quality, it’s not all that simple. Anyone, whether they are an ordinary user, a developer or a tester has its own conception of quality.

There are a great many technologies and software categories, unique projects and its implementation areas, user priorities that need a unique approach to the assessment of software product quality.

If the received results reach a goal and meet expectations, the software product is of high quality. It can be valued with the help of several criteria. They characterize various parts of the program and identify changes in its behavior under the action of some factors.

What are the quality criteria we can’t imagine a good software product?

As a minimum a program should have the right functionality to satisfy a user, work stable, quickly and without errors. It needs to be easy adjusted, easy-to-use and, most importantly, safe.

These characteristics can be named as:

• Functionality
• Reliability
• Efficiency
• Ergonomics
• Mobility
• Maintainability
• Security

Let’s consider them in detail.

1) Functionality. It is the ability of the software product to solve the functional problems. In other words, the program can hardly be called a calculator if it adds and subtracts but doesn’t multiply and divide.

2) Reliability. It is оne of the most important software quality criterion. It determines the ability to function smoothly for a long time at a certain load. In other words, it is a system fault tolerance degree.

Let’s consider the following situation: the customer needs a bridge that can withstand the weight of a certain stream of cars and pedestrians. The bridge is built, but in one year the water washes away some bridge footings. It starts to resonate during the wind strong. As a result it is impossible to pass it.

The product that initially meets the customer’s requirements and performs the tasks, fails to stand the test of time. It is unreliable.

Let’s consider the following situation: the customer needs a bridge that can withstand the weight of a certain stream of cars and pedestrians. The bridge is built, but in a year the water washed away some bridge footings. It started to resonate when the wind was strong. As a result it is impossible to pass it.

The product that initially met the customer’s requirements and performed the tasks, failed to stand the test of time. It is unreliable.

3) Efficiency. It is a product’s ability to solve problems with maximum efficiency at minimum cost resources.

4) Ergonomics. One of the most popular quality criteria for the majority of users. It includes user-friendly interface and usability.

5) Mobility. It is the ability of the program to work in different systems or on different devices without additional expenses and support.

6) Maintainability. Maintainability allows the developer to correct errors and improve the system faster and easier.

7) Security. IT is a security degree of the initial code and personal data from unauthorized access.

Quality assurance can not be overstated while developing a good software. No one will buy a program that is full of errors. Therefore any software creation methodology contains such аn iteration as quality control. The experts can estimate all possible product quality indicators and identify the important errors at the early stages of implementation. It allows to improve the program significantly.

It is important to remember that the excellent software starts from implementation. The formula for success is simple. It contains a precise understanding of the product, clear requirements to functionality, the effective teamwork of the customer, developers, quality assurance engineers and managers.

Original article