Variability in complex systems offering rich set of features is a serious challenge to their users in term of flexibility with many possible variants for different application contexts and maintainability. During the long period of time, much effort has been made to deal with these issues. An effort in this regard is developing and implementing different variability modeling techniques.
This study argues the explanation of three modeling techniques named configurable components, feature models and function-means trees. The main contribution to the research includes:
• A comparison of above mentioned variability modeling techniques in a systematic way,
• An attempt to find the integration possibilities of these modeling techniques based on literature review, case studies, comparison, discussions, and brainstorming.
The comparison is based on three case studies each of which is implemented in all above mentioned three modeling techniques and a set of generic aspects of these techniques which are further divided into characteristics. At the end, a comprehensive discussion on the comparison is presented and in final section some integration possibility are proposed on the basis of case studies, characteristics, commonalities and experience gained through the implementation of case studies and literature review.
Introduction:
Systems offering a broad set of features to their users are very complex and cause serious challenge regarding flexibility and maintainability to their developers and managers. Actually, there are so many variants of the system modules and application contexts, that it is very hard to achieve high flexibility of a system along with maintainability and manageability at the same time.
For example, in the automotive car industry the number of electric and electronic car sub-systems has tripled during the last 20 years. Most of these systems are available with many variants to meet requirements from different countries or to fit to different models of a car manufacture.
A typical case is German car maker BMW which indicated that only 2 cars in two million produced at BMW have exactly the same configuration of subsystems, special equipment or optional parts. Similar is the case for software product lines where more and more lines of codes with different functionality are being added on daily basis.
Variability modeling is not only constrained to mechanics rather it has also been addressed in software industry and service oriented systems. For example, in software industry there are issues related to software product lines, that is, reusable components, alternative modules, interface variations in different versions etc. As long as an organisation develops it processes and gain experience and knowledge, in order to get profit of that knowledge, it needs a way to capture and handle variability in its domain analysis and domain engineering processes.
Handling of all these issues is called Variability Management. Variability management is achieved through variability modeling, and then using it for decision making. There are different variability modeling techniques such as feature modeling, function-means trees, and configurable components in addition to some other approaches. All these variability modeling techniques have their specific area of application, specific set of notations and specific way of implementation where they provide the best suitable solution.
Authors: Qammer Abbas, Asif Akram
Source: Jönköping University