In class practice of software quality assurance and testing

1.CMM And CMMI The relationship between
① What are they
CMMI The full name is ：Capability Maturity Model Integration, Capability maturity model integration .
CMM The full name is ：Capability Maturity Model , Capability Maturity Model .
② The connection between the two
MMI Is in CMM Developed on the basis of , It inherits and develops CMM Excellent characteristics of , Learn from the advantages of other models , Incorporating new theoretical and practical research results . It can not only be applied in the field of software engineering , And it can be used in system engineering and other engineering fields .
③ The difference between the two
CMMI The predecessor of the model is SW-CMM and SE-CMM, The former is what we mean CMM（SW-CMM ）.CMMI And SW-CMM The main difference is that it covers many fields ;CMMI So far, it includes the following four CMM： 　　
（1）、 Software Engineering （SW-CMM） The object of software engineering is the development activity of software system , It is required to realize software development 、 function 、 Systematic maintenance activities 、 Be institutionalized 、 quantitative . 　　
（2）、 Systems engineering （SE-CMM） The object of system engineering is the development activities of the whole system , It may or may not include software . The core of system engineering is to integrate the needs of customers 、 Expectations and constraints are translated into product solutions , And provide full support for the implementation of the solution . 　　
（3）、 Integrated product and process development （IPPD-CMM） Integrated product and process development refers to the product life cycle , Through the cooperation of all relevant personnel , Adopt a systematic process to better meet the needs of customers 、 Expectations and requirements . If the project or enterprise chooses IPPD process , Then you need to select all and IPPD Related practices . 　　
（4）、 purchase （SS-CMM） The content of procurement is applicable to those projects where the behavior of suppliers plays a key role in the success of the project . The main contents include ： Identify and evaluate potential sources of products 、 Determine the target suppliers of the products to be purchased 、 Monitor and analyze the supplier's implementation process 、 Evaluate the work products provided by the supplier and make appropriate adjustments to the supply agreement and supply relationship .
（5）、CMMI Than CMM Multiple I . This I yes intergration, Integration means .CMM It is suitable for the evaluation of organizational maturity of software .CMMI Applicable to a variety of organizational maturity measurement , among CMMI_SW Applicable to software .CMMI relative CMM More complete , More suitable for the big environment .

2. The thought system of software total quality management
① The core concept of total quality management ：
Three core concepts
Customer satisfaction ： The customer is the recipient of the supplied product , It can be internal , It can also be external to the organization .
Added value ： Get the maximum functional value with the minimum investment , Pursue the maximum business performance of the organization and the maximum job performance of individuals .
Continuous improvement ： Set up to PDCA Continuous improvement management system based on circle .
② Quality management development stage
In the continuous development of quality management , It went through three stages .
The first stage , Inspection quality management （19 The end of the century -20 At the beginning of the century ）：
Special quality inspection departments and personnel .
Focus on post inspection .
The products are all produced , You check again , It is too late , Products that fail to pass the inspection will become waste .

So how to improve the yield , The development of quality management has come to the second stage .

The second stage , Statistical quality control （20 century 40 years -20 century 60 years ）：
Emphasis on statistical methods , Based on mathematical statistics .
Get the law through historical data , Guide future projects .
According to these data and some laws , It is found that the quality problem is not a problem in a certain link , More appear in the whole production cycle .

At this time, quality management has developed to the third stage .

The third stage , Total quality management stage （TQM,Total Quality Management）：
Extend quality control to the whole process of product life cycle , Emphasize that all employees participate in quality control .

③ Factors that affect software quality
Software quality iron triangle ： technological process 、 technology 、 organization These three factors are the iron triangle that affects software quality , The improvement of software quality is a comprehensive factor , It needs to be improved in all aspects , At the same time, it also needs to take into account cost and schedule .