Compared with Story Points
the COSMIC method is:
- Consistent between teams and organisations
- Fast – counting CFP manually or automatically is typically faster than story point estimation.
- Suitable for benchmarking
- Has a stronger correlation to effort than SP
Compared with ‘1st Generation’ Functional Size Measurement (FSM) methods
the COSMIC method has the following unique advantages. The method:
- has the widest applicability of any ISO-standard FSM method.
- It was designed to measure business application, real-time, and infrastructure software (such as operating system software) and hybrids of all these types, in any layer of a multi-layer software architecture, and components of these at any level of decomposition. The main 1st generation FSM methods were designed to measure only business software in the application layer;
- uses a model of software based on fundamental software engineering principles. Its basic concepts are therefore compatible with modern methods of determining software requirements and constructing software, and it is ‘future-proof’
- includes a number of approximate variants of the standard size measurement method which can be used for rapid measurement and/or early in the life of a piece of software before all the details of the requirements have been fully defined;
- allows, if required, the measurement of different possible sizes for any one piece of software, e.g. of the whole and of its components, and as ‘seen’ by different ‘functional users’ of the software;
- uses a continuous size scale with no upper bound, unlike some 1st Generation methods which have an arbitrary upper limit to the size scales for their components. Such limits result in a distorted size scale that may lead to under-sizing of software that has large processes;
- is easy to learn, due to the simplicity of the basic concepts. Training on COSMIC is also easy, with many case studies available for training purposes.
- is easy to use. The method’s basic concepts have been carefully defined to eliminate difficulties of interpretation from which earlier FSM Methods suffer. This makes measurement less subjective and more repeatable;
- is completely open. All documentation is available for free download. Translations of the Measurement Manual, which contains all the detailed principles and rules are available or are being prepared in eight languages;
a wide-range of supporting services and tools are available for the COSMIC method, e.g.
- the International Standard ISO/IEC 19761:2010, obtainable from www.iso.org.
- a ‘Method Overview’ document aimed at those who need an introduction to the method;
- guidance and tools for converting sizes from 1st Generation methods;
- approximation variants of the standard method for use in sizing and estimating early in a project life and/or rapid sizing, e.g. of large software portfolios
- certification examinations;
- suppliers of consulting and training services, world-wide;
- case studies;
- estimating tools;
- benchmark data (in the ISBSG database), etc.