Software Design: What is software design?

Software Design: What is software design?

"Wow, design !"

Whenever you talk about this word, will your mind soon pop up with "genius", "inspiration", "creativity "...... In terms of words, some big and round black-rimmed glasses appear simultaneously, while walking up and down, and suddenly two eyes are shining, shouting "I got it" designer image? Even think of artists like Da Vinci and Kiki?

If so, there are two messages to tell you: the bad news is wrong, and the good news is that this article is helpful to you :)

 

"What is design ?"

When answering this question, if you want to open a thick XXX specification or agreement, please let us go away with this idea. We don't need to go to the xxx standard or agreement! @ # ￥ % Definition. No one can understand those definitions and it is useless to understand them. We need plain sayings, but common sayings may be flawed. We need to extract the correct statements from popular sayings.

1 "design is to find a solution to the problem !"

This statement is the most direct and easy to understand, because no matter what design, of course, it is necessary to finally solve the problem. If the problem is not solved, the design itself is wrong, such a design is of course not advisable.

But is design the problem solved?

Certainly not. For example, if you are willing to (you don't need it), you can implement all the functions in the main function to solve all the problems, A main function can be written into tens of thousands or even hundreds of thousands. There is no problem with the function implementation. But in reality, who else writes "Hello, world?

So,"Whether to solve the problem" is the standard for distinguishing between correct and wrong designs, rather than the standard for distinguishing between good designs and poor designs.

2 "design is a genius innovation !"

This is one of the most confusing sayings, which gives many people a feeling of worship to designers. At the same time, I think that I am not a genius, so I cannot design it!

Is there so many problems that can only be solved in a short time? As a matter of fact, you only need to look around and know: is the designer of your team a genius? Are your design friends talented? If you are a designer, do you think you are a genius?

The answer is simple. There are not so many geniuses around you, but there are a lot of designers. Most of the problems around you and me are not solved by Da Vinci, Angela, and Einstein. Design is not an art, nor a scientific research, but an ordinary job. Therefore, you can design it as long as you work hard!

Of course, innovation is indispensable in design. without inspiration and innovation, you cannot go beyond the existing design. With good innovation, you can make a good design! Apple's mobile phone creation time is much shorter than Nokia and Aurora, but Apple's iPhone has set off the world's mobile phone trend. This is the power of innovation!

So,"Genius innovation" is not a necessary condition for design, but a necessary condition for excellence and great design!

3 "The design path is the balance path"

This statement is quite mysterious, but in my experience and understanding, it is the closest to the correct one. The key to understanding this statement is what the "balance" is.

In fact, there is nothing mysterious about it. "balance" is actually the premise of meeting the functional attributes of the demand, how can we balance the quality attributes of a requirement? (for more information about the functional and quality attributes of a requirement, see the story of Demand Analysis in my previous blog post. How can we improve the quality of demand analysis? ).

Why balance quality attributes? Simply put, it is becauseQuality attributes are mutually constrained. When an attribute changes, another attribute will inevitably change, and designers must balance these attributes.

For example, to improve the performance and cost, the cost will increase. It may be the hardware cost (purchase a better and more expensive CPU ), it may also be software costs (software refactoring and rewriting ). In this case, the balance of design is shown. You cannot only consider performance, cost, or cost; only a perfect balance can be obtained between the two. Even the iPhone, which is well-received by Apple, is believed to be more affordable than most people.

However, it is not correct to equate the design with the balance. If we always add, subtract, multiply, and divide the existing things, there will be no innovation, only innovation can solve all quality constraints. For example, if humans always stare at how to increase the speed and capacity of a carriage, then the train will not appear.

 

4. Let's talk about design.

I believe that smart readers can give their answers here. I will summarize them as follows:

Design is an innovative and balanced activity! Either create a new thing to satisfy all requirements, or balance the existing requirements.