PSP – create world-class professional software engineer


Watts Humphrey in 8000 as an engineer in charge of the code, as long as 27 years working for IBM, the personal experience of many successful software development and failure, summarized a series of valuable experience. Under the auspices of the U.S. Department of Defense, he began research in 1986 and 1991, the Capability Maturity Model CMM, software process improvement for the development of the base frame. Shortly after, he realized that the company says that CMM “should,” but did not say the companies, especially the developers “what to do.” In response to this lack, Humphrey was introduced in 1994, Personal Software Process (Personal Software Process, PSP) and Team Software Process (Process software team, TSP). In China, Professor Zhou Bosheng the first time in 1994 in Guangzhou on PSP technology was introduced and in 1999 the TSP technology in Guangzhou the first comprehensive introduction to the system. While the PSP / TSP many software companies large and medium in foreign countries has been widely used and achieved remarkable results, but it is also still in its infancy in China. Well, PSP / TSP to the legal situation in China? They really you? They can give your business that? What are the advantages and disadvantages of developers? What is the role of the project team? Project managers and senior managers in the middle of it? What is the relationship with CMMI? This and the next article with examples and real data to answer these questions.

PSP-promoting people-centered

Most software engineers always like to think of themselves as the elite, advocating individualism code faster and pride. Management project management, they tend to adopt a unified model of rigid imposed engineers who provide poor results. process improvement PSP is the reason for this situation, using a people-centered approach himself as a starting point, I begin. Engineers according to their own situation, I personally gather information on the development of data on the basis to develop the most suitable for their improvement objectives and concrete measures for improvement and self-monitoring. Consciously and continuously improve and strengthen. In theory, this strategy is more efficient, easier to accept.

PSP you can become a professional software engineer best

proceedings of our first lesson in the beginning, one teacher teaches programming skills, students in encoding speed. However, in today’s society, within the prescribed time to develop high quality products, at the request of a promoter more. PSP training is to give developers additional courses, so he (she) had to master the software process management and project management best practices and more advanced, including: accurate estimation of software size, reasonable arrangements for their project development time to time and scope of the project based on sound planning, accurate estimates of time, reduce product defects, measure and monitor their own performance the use of earned value method to monitor progress; honor their commitments, the commitment to resist unreasonable pressure; collect data continuously improve productivity, software quality and schedule predictability , aim to find their weaknesses and improve in time and upward. PSP not only help you improve your coding standards, but also guide you to better the application or process definition, assessment, testing, documentation, etc.. As a developer, if you have these, you’ve probably become a true software engineers. From the point of view of Humphrey, if you follow all standards PSP, you are actually in compliance with CMMI level 5 within the developed software.

PSP is not difficult to learn, you only need 10 days of intensive training, you can have all the skills and access to the world SEI certificate issued by the public. Figure 1 and Figure 2 is a company in Beijing, training developers when partial results. Class of 37 students, each according to the requirements of the PSP, the preparation of 10 small programs, such behavior that estimates of the size and development time. From Figure 1, 2, seen in the program after a 6, we believe that the error was less than 10%. The project team in the development project, we usually start their own estimates, then summarize the average, more or less offset, so that the result will be better.

Figure 1, the formation PSP, estimation errors when the time development

Figure 2, PSP training program errors when estimating size

PSP-extra work will not affect the encoding speed

The introduction of a new process, the developers need to address process issues, such as records of their development time and the number of defects. Companies are most concerned about the direction of one of these will not affect the effectiveness of engineering, such as the encoding speed will not be reduced? Figure 3 data to answer this question as well.

Figure 3

engineers, with or without the encoding speed relative PSP

SEI of 886 developers statistical results, quality objectives specify the number of defects per thousand lines of less than 5, under this principle, programmers do not have a PSP training The process of preparing an average speed of 28.66 is 357 lines / hour, to accept the standard PSP training, the preparation of the 1272 program is average 30.33 lines / hour, not only did not decrease, but increased. Engineers are still part of the encoding speed of more than 100 lines per hour. Some wonder, this seems unlikely, but think, Cai Yong, after PSP, engineers Zuokai O’clock Fa Geng clear logical thinking, planning, design, Deng more complete compilation is reduced to increase productivity but not surprising that De Dao.

PSP-true free lunch

PSP has always been to give priority to the quality control of products, focusing on the development phase of self-assessment and peer review had a bug in all stages of control development to a minimum. Using PSP / TSP, the default rate of the product decreases exponentially (see explanation below others). Figure SEI 3 years of research data and the results confirmed that after the code is written using the PSP will not only reduce the speed, but also a slight rebound, added bonus is that we get quality products, real free lunch.


After many renowned national and international companies checked


technology since 1996 to promote the industrial sector was IBM, Boeing, advanced information services, Teradyne, Motorola, Xerox, Honeywell, ABB and other companies adopted in 1000 and accepted. Last year, Microsoft has officially announced the adoption of PSP / TSP technology, software development and has achieved very good results. Fortunately, in early 2003, Sai Boke technology, China has its first official SEI authorized training division PSP, the PSP is currently training for trainers and TSP launch coach. I think in the near future, the technology more widely in promoting our country.

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