White paper mbre_en
- 2. VISIONEER White Paper MBRE, Feb 22 2 Model-based Requirement Engineering - Concept Description VISIONEER GmbH has developed a revolutionary concept for model- based requirement engineering (MBRE) and a system-kit for embedded systems. Standardized specifications can be created with conventional RE tools (Doors, Polarion, Word...) and extended with simple class notations. The Visioneer MBRE tool identifies these notations and provides a specification-system-kit (classes) for embedded systems. Thus, the specification artifacts themselves become a model that can be handled with object-oriented methods. MBRE Features: • "Easy-to-learn" object-oriented requirement engineering • Automatisms for smart and standardized specifications • Controlled reuse of imported MBSE diagrams, libraries and the elements of a system-kit for embedded systems specifications • Controlled handling of requirements and their solutions / subsolutions • Integrated solutions implementation verification in the specification and in derived work items • Integrated method for controlled description and generation of behavioral requirements • Automatic generation of SW code from the specification Simple notation for object-oriented requirement engineering: By using few textual notations, classes can be generated, derived and converted into specification-artifacts (by instantiation). Fig. 1: Sample class handling in Doors specifications As in the example shown, classes are derived with simple notations and specification-artifacts are generated by instantiation. "The benefit is, that it can clearly be defined with oriented methods, which artifact elements shall be inherited, which are optional or mandatory and which may be changed, extended or deleted "
- 3. VISIONEER White Paper MBRE, Feb 22 3 In the smart specifications, the automatisms (methods) contained in classes are used, enables that: - inherited specification artifacts (text, diagram- or table-elements) are automatically generated - functions its interface requirements and solution assignments are automatically generated in the function description - the specification contents are automatically verified for its completeness, unambiguity and consistency - System MBSE models are imported and merged with library solution classes The controlled reuse of imported MBSE diagrams, libraries and the elements of the system-kit for embedded systems specifications enables a uniquely consistent and standardized structure of specifications according to the basic principle of the "single-source-of-truth". This is realized by a model exchange both within the specification and across model- and work item -boundaries and is thus a significant improvement on today's situation, in which the various work items are only linked. The controlled handling of requirements and their solutions or subsolutions through classes enables: - a clear assignment (automatic linking) of these with each other and the assigned functional entities from which a solution is expected - the simple inheritance of product-specific solutions (experts know- how) and “self-learning” libraries - an automatic verification if all mandatory solution components for all requirements are fully and unambiguously defined in the created specification-artifacts and if they are really implemented in its derived work items (SW code, test protocol, ... ) The proof of implementation can, for example, be carried out before a product release, whereby the following protocol is automatically generated: Fig.2: Automatically generated Requirement Implementation Protocol
- 4. VISIONEER White Paper MBRE, Feb 22 4 However, the most remarkable feature of MBRE is the integrated method for a standardized description of behavioral requirements: For the first time, it has been possible to integrate a method into a RE tool, which provides proof that all behavioral requirements are completely and clearly defined. This is an enormous and very expensive problem for embedded systems applications, as non-existent or misinterpreted requirements undermine the entire quality assurance process and are therefore often discovered by the customer finally. It is so difficult to define them completely and unambiguously for real- time systems, because in any functional description the states of all other parallel behavioral requirements must always be taken into account, which are assigned to the el. control unit simultaneously by different actors. Fig.3: Parallel occurrence of system behavior requirements Practically, there can be many independent actors with multiple states each, and therefore this often results in millions of possible combinations, for which a clear behavior must be defined in any function description separately. Additionally, any individual requirements should be testable, this means it shall be described textually only with the IO signals. The current way to solve these problems is to simulate all pot. IO combinations. However, this requires a very high effort, as the result of each individual combination must be evaluated manually and is therefore only rarely performed. Also, even with this complex procedure, due to the large number of simultaneous events it cannot be ensured, that, the expected (dominant) behavior is really defined in any pot. situation. There is simply no methodology to verify this, as they are only described with IO signals. In MBRE, this is possible for the first time using the integrated method for the description of behavioral requirements: "The idea behind this is that first the dominant behavior of all parallel system behavior requirements shall be clearly described in behavior logic tables and shall then be automatically applied to any individual functional requirement, which is described, for example, with MBSE diagrams" The
- 5. VISIONEER White Paper MBRE, Feb 22 5 Out of the defined behavior logic tables in conjunction with the functional descriptions, the automatic generation of guaranteed complete, unambiguously and testable behavior requirements and their derived requirements for the real-time scheduler is performed: Fig.4: Automatically generated behavior requirements Conclusion Through the many integrated automatisms and the performed verifications, Model Based Requirement Engineering enables both, a significant saving of engineering efforts and an enormous increase in the quality of the product to be developed. "MBRE can be seen as the missing link between MBSE and MBSA (like AutoSar) in their approach to generate SW for Embedded Systems out of MBSE models " More questions? Contact: Gerhard Schilling, Phone +49 179-324 5588 [email protected] www.visioneer.info