Mumbai University > Computer engineering > Sem 7 > Software Architecture.

Marks: 10M

Year: Dec14, May14, Dec13

Model-based analysis:

Model based architectural analysis techniques depend on a system’s architectural description and manipulate that description to discover properties of the architecture. As they are tool-driven, the cost is less.

• Goals: consistency, compatibility and internal completeness. The goals also include certain aspect of external completeness and correctness.
• Scope: It can span individual components and connectors, their compositions in a specific subsystem or the entire system as well as the data exchanged among the specific components and connectors or across the entire architecture.
• Concern: The specific concern of the analysis can vary. The techniques may focus on the structural, behavioral or interaction properties. Behavioral and interaction properties may be difficult to access completely using this technique alone, thus they are coupled with simulation based analysis approach.
• Type: The type of analysis for which model based analysis is best suited is for static analysis. These techniques can be used to assess properties such as proper connectivity, type conformance, interface and behavioral conformance between interacting components, deadlock freedom, etc.
• Automation level: These techniques are at least partially automated and are often fully automated, requiring no human intervention.

This technique can be used to establish hard properties of the system’s architecture, which are the properties that can be encoded in the architectural model. Another concern with model-driven analysis technique is their scalability. More complex techniques are required to keep track of very large number of the modeled system’s elements and properties. Model based analysis usually does not provide all needed answers and is coupled with techniques from other two categories- inspections and reviews and simulation-based analysis. The architectural models include wright, rapide, Darwin, MetaH, UniCon etc.

Simulation-based analysis:

Simulation requires producing a dynamic, executable model of a given system or of a part of the system that is of particular interest, possibly from a source model that is otherwise not executable.

• Goals: completeness, consistency, compatibility or correctness. But these properties can be established only with a limited degree of confidence and possibly only for a particular subsystem or system property.
• Scope: It is the entire system or a particular subsystem and the dataflow in the system. However, it is possible to isolate individual components and connectors and simulate their behavior.
• Concern: it spans behavior, interaction and non-functional properties.
• Type: The simulation based analysis is best suited for dynamic analysis, scenario-based analysis in particular. They are well suited in assessing the system’s run time behavior, interaction characteristics and non functional qualities.
• Automation level: This technique is typically fully automated, requiring no human intervention other than applying system inputs. However, the process of mapping the architectural model to simulation model requires considerable human involvement.

Simulation based analysis requires that the architectural models be formal. It is not possible to map the informal models to the necessary simulation substrate. This technique can be useful to all system stakeholders. Setting up and running simulation need a high degree of technical expertise and familiarity with architectural models, modeling notation and simulation substrate. Simulation models and environment includes StateMate, Matlab, Adevs, Emulab etc.