Reprint: Measurement of software quality

This article is from: http://jerry051635.iteye.com/blog/1235988

How to measure the quality of software is a difficult question to answer, in the end, you are the standard to promise the quality of this software good? Milk, as long as it contains a certain amount of nutrients, and the harmful ingredients do not exceed a certain standard, then we say that the quality of the milk is qualified. How to embody the quality of software?

Let's take a look at what is the quality of software, software quality is a clear statement of the functional and performance requirements, clear record of the development standards and to all professional development should have the implicit characteristics of the degree of compliance. It emphasized the following threefold meanings:

1. The requirements of the software are the basis of quality, and the lack of quality is not in line with the requirements.

2. The software process must follow some development standards and industry standards.

3. The software must meet the implied requirements.

In accordance with these three points, we can say that there is quality.

One thing is certain, we can not directly measure the quality of the software, we can only be measured by some specific quality characteristics of the software. Then we set the standard for these quality characteristics, so we built up the concrete quality measure standard. The standard of quality measurement can also be called the quality model, which is the core part of the quality management process. Two kinds of commonly used quality measurement models are introduced.

(i) McCall quality measurement model

The quality characteristics of McCall and others are defined as follows:

McCall Software Quality Model

(ii) ISO 9126 quality measurement model

The model divides the quality characteristics into six areas:

1. Function: suitability, accuracy, interoperability, compliance and safety;
2. Reliability: maturity, fault tolerance and ease of recovery;
3. Easy to use: Easy to understand, easy to learn habits and ease of operation;
4. Efficiency: Time characteristics and resource characteristics;
5. Maintainability: Easy to analyze, easy to change, stability and ease of testing;
6. Portability: Adaptability, ease of installation, consistency and ease of substitution.

In summary, these mass properties can be divided into two categories, which can be directly tested and indirectly tested. For the function, performance and so on we can directly test, for ease of use, reliability, etc., we need to find a way through a certain path, which is the blind spot of our current testing, of course, our quality personnel need to solve the problem. (companies that do not include demand management do not have a clear quality profile, and there is no need to explore other things).

So what do we expect from these quality features at that stage of the software process? Which is the time to set the test target. This is also a controversial issue. On the one hand, it should be expected to establish quality characteristics in the early stage, but opponents believe that many of the early quality characteristics are not obvious and unstable, and the late establishment of quality of heat, it is inevitable that there are preconceived drawbacks.

In view of the current domestic quality management is not standardized, there is no fixed standard. I think we should build these quality traits later on. That is, after the stability of demand is established. These quality characteristics are developed by quality personnel, which excludes the testers themselves from setting goals for themselves. That is, the quality of personnel in the clear requirements, the software has developed a set of quality factors, to show that as long as the software to achieve these quality factors, then it is quality qualified, and testers are only responsible for the use of specific testing methods to verify that the actual and objective is in line with the relationship.

In fact, testers can work more easily, rather than set their own goals to torture themselves;

In fact, quality personnel should play a greater role, rather than now simply tracking progress and testing defects ...

Reprint: Measurement of software quality