Cmm Level 5 Software Companies

Computer.org/dl/mags/so/2008/03/figures/mso20080300371.gif' alt='Cmm Level 5 Software Companies' title='Cmm Level 5 Software Companies' />Software Quality Metrics Overview Product Quality Metrics. In this chapter from his book on software quality engineering, Stephen H. CMMI-Core-Process-Areas.png' alt='Cmm Level 5 Software Companies' title='Cmm Level 5 Software Companies' />Kan discusses several metrics in each of three groups of software quality metrics product quality, in process quality, and maintenance quality. He also describes the key metrics used by several major software developers and discusses software metrics data collection. This chapter is from the book Software metrics can be classified into three categories product metrics. Product metrics describe the. Process metrics can be used to improve software. Examples include the effectiveness of defect. Project metrics describe the project. Examples include the number of software. Some metrics belong to multiple categories. For. example, the in process quality metrics of a project are both process metrics. Software quality metrics are a subset of software metrics that focus on the. In general, software. Nonetheless, the project parameters such as the. Software. quality metrics can be divided further into end product quality metrics and. The essence of software quality engineering is to. Moreover, we should view quality from the. In this chapter we discuss several metrics. In the last sections we also describe the key. As discussed in Chapter 1, the de facto definition of software quality. The. metrics we discuss here cover both levels Mean time to failure. Defect density. Customer problems. Customer satisfaction. Intrinsic product quality is usually measured by the number of. In operational. definitions, the two metrics are defect density rate and mean time to failure. MTTF. The MTTF metric is most often used with safety critical systems such as. Planet ECom Solutions Pvt. Ltd. A Microsoft Certified ISO 9001 Web Development Company in India, UK Providing Software, Mobile Application Development, CMS Services. Resonses to Top five IT companies, Software exporters in the Lahore, Punjab Pakistan. Milestones. Wipro, one of the worlds most trusted brands, is a name with a long history. Heres a snapshot of our journey to date 2016 Wipro Acquires. For instance, the. U. S. government mandates that its air traffic control system cannot be. In civilian airliners, the. Littlewood and Strigini, 1. The defect density metric, in. The two metrics are correlated but are different enough to merit close. First, one measures the time between failures, the other. Second, although it is difficult to separate defects and. According to the IEEE American National. Standards Institute ANSI standard 9. An error is a human mistake that results in incorrect software. The resulting fault is an accidental condition that causes a unit of the. A defect is an anomaly in a product. A failure occurs when a functional unit of a software related system can. From these definitions, the difference between a fault and a defect is. For practical purposes, there is no difference between the two terms. Indeed, in many development organizations the two terms are used synonymously. In this book we also use the two terms interchangeably. Simply put, when an error occurs during the development process, a fault or a. In operational mode, failures are caused by. Sometimes a fault. Therefore, defect and failure do not have a one to one. Third, the defects that cause higher failure rates are usually discovered and. The probability of failure associated with a latent defect is. For special purpose software systems. Excel Templates Create. For general purpose computer systems or. MTTF metric is more difficult to implement and may not be. Fourth, gathering data about time between failures is very expensive. It. requires recording the occurrence time of each software failure. It is sometimes. quite difficult to record the time for all the failures observed during testing. To be useful, time between failures data also requires a high. This is perhaps the reason the MTTF metric is not widely. Finally, the defect rate metric or the volume of defects has another appeal. The defect rate of a product. Regardless of their differences and similarities, MTTF and defect density are. Accordingly, there are two. We discuss the two types of. Chapter 8. 4. 1. 1 The Defect Density Metric Although seemingly straightforward, comparing the defect rates of software. In this section we try to articulate the major. To define a rate, we first have to operationalize the numerator and the. As discussed in Chapter 3, the general. OFE during a specific time frame. We have just discussed the definitions of. Because failures are defects materialized, we can. The denominator is the size of the software, usually. KLOC or in the number of function points. In terms of time frames, various operational definitions are used for the life. LOP, ranging from one year to many years after the software. In our experience with operating. For application software, most defects are normally. Lines of Code The lines of code LOC metric is anything but simple. The major problem. In. the early days of Assembler programming, in which one physical line was the same. LOC definition was clear. With the availability of. Differences. between physical lines and instruction statements or logical lines of code and. LOCs. Even within the same language, the methods and algorithms used by different. Jones. 1. 98. 6 describes several variations Count only executable lines. Count executable lines plus data definitions. Count executable lines, data definitions, and comments. Count executable lines, data definitions, comments, and job control. Count lines as physical lines on an input screen. Count lines as terminated by logical delimiters. To illustrate the variations in LOC count practices, let us look at a few. In Boehms well known book. Software Engineering Economics 1. LOC counting method counts. In Software Engineering Metrics and Models by Conte et al. LOC is defined as follows A line of code is any line of program text that is not a comment or blank. This specifically includes all lines containing program headers. Thus their method is to count physical lines including prologues and data. In Programming Productivity. Jones 1. 98. 6, the source instruction or logical lines of code method. The method used by IBM Rochester is also to count source instructions. The resultant differences in program size between counting physical lines and. It is not even known. In some languages such as BASIC. PASCAL, and C, several instruction statements can be entered on one physical. On the other hand, instruction statements and data declarations might span. Languages. that have a fixed column format such as FORTRAN may have the. According to Jones. In contrast. for COBOL the difference is about 2. There are strengths and weaknesses of physical LOC and logical LOC Jones. In general, logical statements are a somewhat more rational choice for. When any data on size of program products and their quality are. LOC counting should be described. At the minimum, in. LOC data is involved, the author should state. LOC counting method is based on physical LOC or logical LOC. Furthermore, as discussed in Chapter 3, some companies may use the straight. LOC count whatever LOC counting method is used as the denominator for. Assembler equivalent LOC based on some conversion ratios for the. Therefore, industrywide standards should include the conversion. Assembler. So far, very little research on. The conversion ratios published by Jones 1. As more and more high level languages. When straight LOC count data is used, size and defect rate comparisons across. Extreme caution should be exercised when comparing. LOC, defects, and time frame are not identical. Indeed, we do not recommend such. We recommend comparison against ones own history for the sake. NOTEThe LOC discussions in this section are in the context of defect rate. For productivity studies, the problems with using LOC are more. A basic problem is that the amount of LOC in a softare program is. The purpose of software is to.