COSMIC functional size measurement
COSMIC Functional Size Measurement is a method to measure a standard functional size of a piece of software
COSMIC may also refer to the COmmon Software Measurement International Consortium, a voluntary organization that has developed the method and is still expanding its use to more software domains.
The COSMIC method
The COSMIC method defines the principles, rules and a process for measuring a standard functional size of a piece of software. Functional size is a measure of the amount of functionality provided by the software, completely independent of any technical or quality considerations. The generic principles of functional size are described in the [1] standard. The COSMIC method is also an International Standard by itself. The [2] standard is the first second generation implementation of the ISO/IEC 14143 standard. There are also four first generation implementations:
- ISO/IEC 20926 - IFPUG function points
- ISO/IEC 20968 - Mk II function points
- ISO/IEC 24570 - Nesma function points
- ISO/IEC 29881 - FiSMA function points
The method in a nutshell
The COSMIC method may be used to size software that is dominated by functionality to maintain data, rather than software that predominantly manipulates data. The method can be used in a wide variety of domains, like business applications, real-time software, mobile apps, infrastructure software and operating systems. The method translates the Functional User Requirements of the software to four types of base functional components:
- Entry (E)
- Exit (X)
- Read (R)
- Write (W)
The method structure
The foundation of the method is the ISO/IEC 19761 standard, which contains the definitions and basic principles of the method. The detailed guidelines of the method are laid down in a Measurement Manual that is independent of any software domain. For different domains underlying guidelines are available:
To explain the use of the method a number of case studies have been developed:
- Real-time - Automatic line switching
- Real-time - Valve control
- Real-time - Rice cooker
- Business - Car hire
- Business - Course registration
- Business - Web advice module
The organization behind the method
The COSMIC organization commenced its work in 1998. Legally COSMIC is an incorporated not for profit organization under Canadian law. The organization grew informally to a global community of professionals. COSMIC is an open and democratic organization. The organization relies and will continue to rely on unpaid efforts by volunteers, who work on various aspects of the method, based on their professional interest.
Second generation
The first generation Functional Size Measurement methods consist of rules that are based on empirical results. Some define their own terminology, which may have overlap with other terms in software engineering. They work well for the software domains the rules were designed for, but for other domains, the rules need to be altered or extended. Key elements of a second generation Functional Size Measurement method are:
- Adoption of all measurement concepts from the ISO metrology
- A defined measurement unit
- Fully compliant with ISO/IEC 14143
- Preferrably domain independent
The COSMIC method is based on principles rather than rules that are domain independent. The principles of the method are based on fundamental software engineering principles, which have been subsequently tested in practice.
- ^ ISO/IEC JTC 1/SC 7 Software and systems engineering (2007-02-01). "ISO/IEC 14143". International Standards Organization. Retrieved 2018-06-13.
{{cite web}}: CS1 maint: numeric names: authors list (link) - ^ COSMIC (2003-02-19). "ISO/IEC 19761". International Standards Organization. Retrieved 2018-06-13.