2018年/12月/02日

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一些事实

不知道是哪个老外写的，也不知道是谁翻译的，总之，这些事实让我觉得挺可怕的，软件从何处开始腐烂？从概念完整性缺失的时候

• Averaging over the lifetime of the project, a programmer spends about 10-20% of his time writing code, and most programmers write about 10-12 lines of code per day that goes into the final product, regardless of their skill level. Good programmers spend much of the other 90% thinking, researching, and experimenting to find the best design. Bad programmers spend much of that 90% debugging code by randomly making changes and seeing if they work.

• A good programmer is ten times more productive than an average programmer. A great programmer is 20-100 times more productive than the average. This is not an exaggeration – studies since the 1960’s have consistently shown this. A bad programmer is not just unproductive – he will not only not get any work done, but create a lot of work and headaches for others to fix.

• “A great lathe operator commands several times the wage of an average lathe operator, but a great writer of software code is worth 10,000 times the price of an average software writer.” –Bill Gates

• Great programmers spend little of their time writing code – at least code that ends up in the final product. Programmers who spend much of their time writing code are too lazy, too ignorant, or too arrogant to find existing solutions to old problems. Great programmers are masters at recognizing and reusing common patterns. Good programmers are not afraid to refactor (rewrite) their code to reach the ideal design. Bad programmers write code which lacks conceptual integrity, non-redundancy, hierarchy, and patterns, and so is very difficult to refactor. It’s easier to throw away bad code and start over than to change it.

• Software development obeys the laws of entropy, like any other process. Continuous change leads to software rot, which erodes the conceptual integrity of the original design. Software rot is unavoidable, but programmers who fail to take conceptual integrity into consideration create software that rots so so fast that it becomes worthless before it is even completed. Entropic failure of conceptual integrity is probably the most common reason for software project failure. (The second most common reason is delivering something other than what the customer wanted.) Software rot slows down progress exponentially, so many projects face exploding timelines and budgets before they are mercifully killed.

• A 2004 study found that most software projects (51%) will fail in a critical aspect, and 15% will fail totally. This is an improvement since 1994, when 31% failed.

• Although most software is made by teams, it is not a democratic activity. Usually, just one person is responsible for the design, and the rest of the team fills in the details.

• Programming is hard work. It’s an intense mental activity. Good programmers think about their work 24/7. They write their most important code in the shower and in their dreams. Because the most important work is done away from a keyboard, software projects cannot be accelerated by spending more time in the office or adding more people to a project.

1. 一个程序员用在写程序上的时间大概占他的工作时间的10-20%，大部分的程序员每天大约能写出10-12行的能进入最终的产品的代码——不管他的技术水平有多高。好的程序员花去90%的时间在思考、研究和实验，来找出最优方案。差的程序员花去90%的时间在调试问题程序、盲目的修改程序，期望某种写法能可行。

   ”一个卓越的车床工可以要求比一个一般的车床工多拿数倍高的工资，但一个卓越的软件写手的价值会10000倍于一个普通的写手。“——比尔盖茨

2. 一个好的程序员的效率会是一个普通的程序员的十倍之上。一个伟大的程序员的效率会是一个普通程序员的20-100倍。这不是夸张—— 1960年以来的无数研究都一致的证明了这一点。一个差的程序员不仅仅是没效率——他不仅不能完成任务，写出的大量代码也让别人头痛的没法维护。

3. 伟大的程序员只花很少的时间去写代码——至少指那些最终形成产品的代码。那些要花掉大量时间写代码的程序员都是太懒惰，太自大，太傲慢，不屑用现有的方案去解决老问题。伟大的程序员的精明之处在于懂得欣赏和重复利用通用模式。好的程序员并不害怕经常的重构（重写）他们的代码以求达到最好效果。差的程序员写的代码缺乏整体概念，冗余，没有层次，没有模式，导致很难重构。把这些代码扔掉重做也比修改起来容易。

4. 软件遵循熵的定律，跟其它所有东西一样。持续的变更会导致软件腐烂，腐蚀掉对原始设计的完整性概念。软件的腐烂是不可避免的，但程序员在开发软件时没有考虑完整性，将会使软件腐烂的如此之快，以至于软件在还没有完成之前就已经毫无价值了。软件完整性上的熵变可能是软件项目失败最常见的原因。（第二大常见失败原因是做出的不是客户想要的东西。）软件腐烂使开发进度呈指数级速度放缓，大量的软件在失败之前都是面对着突增的时间要求和资金预算。

5. 2004年的一项研究表明大多数的软件项目（51%）会在关键功能上失败，其中15%是完全的失败。这比1994年前有很大的改进，当时是31%。

6. 尽管大多数软件都是团体开发的，但这并不是一项民主的活动。通常，一个人负责设计，其他人负责实现细节。

7. 编程是个很难的工作。是一种剧烈的脑力劳动。好的程序员7×24小时的思考他们的工作。他们最重要的程序都是在淋浴时、睡梦中写成的。因为这最重要的工作都是在远离键盘的情况下完成的，所以软件工程不可能通过增加在办公室的工作时间或增加人手来加快进度。