Read Software Engineering thoughts 2

System Design
System design is the most important part of converting requirements into software systems. The advantages and disadvantages of system design fundamentally determine the quality of software systems. Like "All imperialism is a paper tiger", we can conclude that "poor system design must produce poor software systems ." Therefore, we must strive to ensure that the system design is "rooted in strength" and eliminate all design trends that are left and right in the bud.
This chapter describes four aspects of system design: architecture design, module design, data structure and Algorithm Design, user interface design. If the software system is compared to the human body, then:
(1) The architecture is like the skeleton of a single person. If a guy's skeleton is a monkey, then no matter how feeding and beauty, this guy is always a monkey and will not become a human.
(2) A module has specific functions, just like an organ of the same person. One of the most outstanding modules in the human body is the hand, which has only a few actions, but can do unlimited things. One of the worst modules in the human body is the mouth, which integrates the most valuable but unrelated functions such as eating, talking, and kissing, so that they cannot be processed in parallel. This is really unfortunate for humans.
(3) data structures and algorithms are like the blood and nerves of the same person. They allow the organs to live and function. Data structures and algorithms are distributed in the architecture and modules. They coordinate various functions of the system. Although the ears and mouth of a person are relatively independent organs, if the ears become deaf, the mouth can only make a sound of "ah" and "wow, it is equal to the loss of the ability to speak (so deaf people are born to be dumb), but people can use gestures instead of speaking. The human body's data structure and algorithm design are amazing and ridiculous.
(4) The user interface is like the appearance of a person, which is the easiest way to make people fall in love at first sight or get sick at first sight. As we are pursuing the beauty of mind and appearance, software systems are also pursuing (internal) powerful functionality and (external) friendly interfaces. However, as the pace of life accelerates, people are less interested in tasting the hidden inner beauty. If the UNIX system is compared to a strong man and a woman, then the Windows system is like a charming white face and a fox. Unexpectedly, the Windows system was able to take over the market. In view of this, we should encourage women to buy more cosmetics (men pay) for a better interface.
During system design, we need to pay close attention to software quality factors, such as correctness and accuracy, performance and efficiency, ease of use, comprehensibility and conciseness, reusability and scalability. Even if the system is well designed, it does not mean that a good software system can be generated. In Program A lot of work needs to be done in the design, testing, and maintenance processes. No matter which part of the process is wrong, it will be a good thing. It is said that God has designed all the ladies as angels, but when the angels fall down, some feet first touch the ground, and some faces first touch the ground. God's negligence has hurt many girls. We must learn this lesson when developing software.