Formal Methods for Quality of Service Analysis

Component-Based Software Architecture is a promising solution for distributed computing. To develop high quality software, analysis of non-functional aspects of the software properties (also called Quality of Service or QoS) is very important. The UniFrame research project proposes a Unified Component Meta-Model Framework (UniFrame) that includes QoS contracts. A classification of QoS parameters, both static and dynamic, relevant to component-based distributed computing is proposed and represented formally using Two-Level Grammar (TLG), an object-oriented formal specification language. TLG may be transformed into both a UML model, augmented with OCL constraints, and executable code in the Java programming language. This may be regarded as standardized code for implementation of the distributed application with dynamic measurement of the QoS aspects incorporated. The approach is consistent with OMG’s Model Driven Architecture (MDA) in that QoS properties may be specified at the Platform Independent Model (PIM) level and then carried down to the Platform Specific Model (PSM) level in implementation.