What is the underlying logic of software quality management?

Original Zhu Shaomin  software quality report 2021-12-10 08:19 

The entire software industry is developing rapidly, pursuing rapid iteration and rapid release, but the speed cannot be infinitely enlarged, and when the competition reaches a certain level, the whole world will be filled with the same products or similar services, and human beings must choose the best products/ Service, we have to return to the original point after all.

When an opportunity comes, we often study how to use a set of strategies to seize the opportunity faster than others, and how to run faster than others to seize the market.

However, in the end we still have to rely on the quality of the product to win. I'm still happy to use Lei Jun's slide again to further explain the need to discuss: what is the underlying logic of quality management.

— 1 —

What is "quality"?

Speaking of quality, everyone seems to be familiar with it, but if you want to explain the quality clearly, you may not be able to clearly explain the quality, because it is not simply good or bad.

With the advancement of social productivity and the continuous deepening of people's understanding, people's understanding of the concept of quality is also constantly updated and developed. The evolution of quality cognition can be briefly introduced:

1. Quality 1.0 - the concept of conformity quality: in the last century, the traditional concept of quality basically refers to whether the product performance meets the technical specifications, that is, the quality characteristics of the product are compared with the technical specifications to " conform" to the current standard As a measure, the degree of "compliance" reflects the consistency of product quality . If the quality characteristics are within the tolerance range of the specification value, it is a qualified product or a high-quality product; if it exceeds the tolerance range, it is a substandard product or a defective product. This is the so-called "Goalpost" (Goalpost), also That is, compliance quality control.

2. Quality 2.0 - the concept of applicability quality : but for high-tech and large-scale complex products, conformity quality control can no longer meet the requirements of quality management, so the world-renowned American quality management guru Joseph M. Juran (Joseph M. Juran) proposed The quality of the product is the point of view of fitness for use. The so-called applicability is the degree to which the product meets the customer's requirements during use. To satisfy customers, not only meet the requirements of standards and specifications, but also meet other requirements of customers, including implicit requirements . Moreover, the development of quality from "conformity" to "applicability" makes people gradually put customers' needs in the first place in their understanding of quality .

3. Quality 3.0 - the concept of broad quality : Dr. Juran's definition of quality has gradually evolved into an internationally standardized definition. The International Organization for Standardization summarizes and refines different concepts of quality, and gradually forms commonly recognized terms, which not only reflect the requirements of standards, but also meet the needs of customers, and integrate the meanings of conformity and applicability. The definition of quality in the ISO9000 series of international standards ((2000 version): quality is the degree to which a set of inherent characteristics meet requirements (expressed, usually implied, or must be fulfilled requirements or expectations). The ISO 9000 series of standards emphasize quality:

• Focus on customers, aim to enhance customer satisfaction, and ensure that customer requirements are determined and met;

• Provide products that meet customer and applicable legal and regulatory requirements;

• Understand and meet the current and future needs and expectations of existing and potential customers and end users, as well as understand and consider the current and future needs and expectations of other interested parties;

• keep improve.

In 1988, Zaithaml proposed the theory of Customer Perceived Value (CPV) from the perspective of customers, and summarized four meanings of perceived value:

1. Value is low price. Some customers equate value with low price, indicating that the currency being paid is most important in their perception of value.

2. Value is what customers want from a product. Instead of focusing on the money paid, some customers will view the benefits they receive from a service or product as the most important value factor. This is actually the same as the definition of utility in economics, a subjective measure of the degree of satisfaction gained from consuming a product.

3. Value is the quality that customers pay for. Some customers understand the concept of value as a trade-off between "money paid" and "quality" obtained.

4. Value is all that customers can get for all their efforts. Some customers describe value in terms of both what they paid (time, money, effort) and the benefits they received.

There are other understandings of quality, such as consistency , the better the consistency, the higher the quality of the product, and the smaller the difference between products , which is where 6 Sigma comes from. This kind of cognition is suitable for industrially produced products, because products of the same design will produce tens of thousands, hundreds of thousands or even billions of copies, but this kind of cognition is not suitable for software products , because every software product is different Yes, the same product copy will not produce a difference.

If you want to learn more about what quality is, you can check out these articles:

• Three questions about quality

• Complete Interpretation of Software Quality Model

• In the new era, re-understand the value of quality and testing

• Many people are foolishly confused about "business requirements, user requirements and system requirements"

• I have to talk about the first major quality accident of the Lunar New Year: GitLab lost data

— 2 —

What is "Quality Management"?

To understand what quality is, we need to understand what is "quality management".

Before talking about what quality management is, let me tell you a familiar story:

During the Spring and Autumn Period and the Warring States Period, there was a genius doctor who was honored as the "ancestor of medicine", and he was "Bian Que". Once, King Wen of Wei asked Bian Que, "The three brothers in your family are all good at medicine. Which one is the best?" Bian Que replied, "The elder brother is the best, the second brother is the second, and I am the worst." King Wen asked again: "Then why are you the most famous?" Bian Que replied: "The elder brother cures the disease before the disease breaks out. Because most people don't know that he can eradicate the disease beforehand, so his fame cannot be spread; Brother treats diseases at the beginning of the disease, and most people think that he can only cure minor illnesses, so his reputation only reaches the local people; but I treat diseases when the disease is serious, and most people see me in the hospital. I put needles on the meridians to let blood, apply medicine on the skin and other major operations, so I think my medical skills are superb, so I am famous all over the country.”

To understand quality management, we need to discuss it together with quality control and quality assurance, because quality control and quality assurance are the basis of quality management. When people start to pay attention to software quality management, they first think of quality inspection and quality control, and then gradually realize prevention Problems are more important than finding them after the fact, resulting in three levels of quality management:

1. Quality Control (Quality Control, QC) is the basic method to scientifically measure the state of the process. Just like the instrument on the dial of a car, you can know the speed, speed, oil level, etc. during driving. 

2. Quality Assurance (QA) is a collection of references and guidelines for processes and procedures. ISO 9000 is one of a kind, like an owner's manual in a car. 

3. Quality Management (QM) is the philosophy of operation, teaching you how to drive, establishing quality culture and management thinking.

In order to understand the quality work level more easily, the four levels of quality management can be simply explained from another aspect as follows:

1. Inspection, to ensure the quality of products through inspection, products that meet the specifications are qualified products, products that do not meet the specifications are defective products, and defective products cannot be sold. This level is characterized by independent quality work, and quality is a matter of the quality department and inspectors. Inspection of products is only to judge product quality, without inspection of process flow, design, service, etc., product quality cannot be improved. This level is the initial stage, which is equivalent to "software testing - early software quality control";

2. Guarantee, the quality goal is achieved through the R&D, design and manufacturing departments, start to define the quality goal and quality plan, and ensure the rationality, fluency and stability of the development process. But there is little measurement work, and the requirements and design quality are unclear.

3. Prevention, focus on prevention, focus on process management, focus on quality assurance work on process management, introduce preventive thinking from product demand analysis and design, face customer characteristics, greatly reduce the cost of low quality, quite Based on mature "software quality assurance";

4. Perfection, customer-centric, full participation, and pursuit of excellence are equivalent to "total quality management" and "zero defect quality management".

You can also refer to these articles to better understand software quality management.

• Where did the test come from and where did it go?

• What is the underlying logic of software testing?

• Stop! Quality can be assessed, not measured

• Part one of the series "How the world's best companies manage quality": Google's three pillars of quality

• How did a company with a market value of one trillion rise rapidly relying on quality and just one good product?

— 3 —

The underlying logic of quality management

According to the cognition of "quality" and "quality management" above today, we know that quality exists because of customers, quality is customer satisfaction, quality is judged by customers, and the more satisfied customers are with the products, the better the product quality is. Quality management is to do work around customers and continuously improve customer satisfaction.

Therefore, understanding the underlying logic of quality management from this perspective is: quality management is to continuously deepen the understanding of customers, identify customers, analyze customer behavior, characterize customers and gain insight into customers.

In the third report of the series "How Excellent Companies in the World Manage Quality": Adhere to the customer first, Amazon is consistent. The  article talks about a practice of Amazon. In any conference room, there is always a red empty space. The chair was given to the customer, but the customer did not come, but everyone always thought that the customer was by his side and was participating in the meeting.

Even if you have a good understanding of customers, you may not be able to produce the products that customers want. At this time, you need to build capabilities to achieve high-quality delivery. From this perspective, the underlying logic of quality management is: quality management is to build the ability to deliver high quality, including the technical capabilities of R&D personnel, quality assurance processes, infrastructure (assembly line) capabilities, etc.

I wrote an article before: In addition to the three quality questions, how to deal with the five soul tortures of quality management? Does the answer to these five soul tortures represent the underlying logic of the five quality managements?

1. What is the value of quality?

2. How is the value of quality measured?

3. How to define quality goals?

4. How to connect quality indicators and business indicators?

5. How to do a good job in quality management?

For example, the answer to the last torture is:

   

It can also be seen from this that the underlying logic of quality management is to use systems engineering methods to build quality, prevent defects, track quality, and solve quality problems. This is why we wrote the "White Paper on Software Quality Engineering in the Digital Era".