Software system

software system is a system of intercommunicating components based on software forming part of a computer system (a combination of hardware and software). It "consists of a number of separate programs, configuration files, which are used to set up these programs, system documentation, which describes the structure of the system, and user documentation, which explains how to use the system". The term "software system" should be distinguished from the terms "computer program" and "software". The term computer program generally refers to a set of instructions (source, or object code) that perform a specific task. However, a software system generally refers to a more encompassing concept with many more components such as specification, test results, end-user documentation, maintenance records, etc. The use of the term software system is at times related to the application of systems theory approaches in the context of software e

An Ontology-Based Approach for Closed-Loop Product Lifecycle Management

Aristeidis Matsokis

The main goal of the Product Lifecycle Management (PLM) is the management of all the data associated to a product during its lifecycle. Lifecycle data is being generated by events and actions (of various lifecycle agents which are humans and/or software systems) and it is distributed along the product's lifecycle phases: Beginning of Life (BOL) including design and manufacturing, Middle of Life (MOL) including usage and maintenance and End of Life (EOL) including recycling, disposal or other options. Closed-Loop PLM extends the meaning of PLM in order to close the loop of the information among the different lifecycle phases. The idea is that information of MOL could be used at the EOL stage to support deciding the most appropriate EOL option (especially to make decision for re-manufacturing and re-use) and combined with the EOL information it could be used as feedback in the BOL for improving the new generations of the product. Several PLM models have been developed utilising various technologies and methods towards providing aspects of the Closed-Loop PLM concept. Ontologies are rapidly becoming popular in various research fields. There is a tendency both in converting existing models into ontology-based models, and in creating new ontology-based models from scratch. The aim of this dissertation is to include the advantages and features provided by the ontologies into PLM models towards achieving Closed-Loop PLM. Hence, an ontology model of a Product Data and Knowledge Management Semantic Object Model for PLM has been developed. The transformation process of the model into an ontology-based one, using Web Ontology Language-Description Logic (OWL-DL), is described in detail. The background and the motives for converting existing PLM models to ontologies are also provided. The new model facilitates several of the OWL-DL capabilities, while maintaining previously achieved characteristics. Furthermore, case studies based on various application scenarios, are presented. These case studies deal with data integration and interoperability problems, in which a significant number of reasoning capabilities is implemented, and highlight the utilisation of the developed model. Moreover, in this work, a generic concept has been developed, tackling the time treatment in PLM models. Time is the only fundamental dimension which exists along the entire life of an artefact and it affects all artefacts and their qualities. Most commonly in PLM models, time is an attribute in parts such as "activities" and "events" or is a separate part of the model ("four dimensional models"). In this work the concept is that time should not be one part of the model, but it should be the basis of the model, and all other elements should be parts of it. Thus, we introduce the "Duration of Time concept". According to this concept all aspects and elements of a model are parts of time. Case studies demonstrate the applicability and the advantages of the concept in comparison to existing methodologies.

EPFL2010

Model refactoring using transformations

Slavisa Markovic

Modern software is reaching levels of complexity encountered in biological systems; sometimes comprising systems of systems each of which may include tens of millions of lines of code. Model Driven Engineering (MDE) advocates raising the level of abstraction as an instrument to deal with software complexity. It promotes usage of software models as primary artifacts in a software development process. Traditionally, these MDE models are specified by Unified Modeling Language (UML) or by a modeling language created for a specific domain. However, in the vast area of software engineering there are other techniques used to improve quality of software under development. One of such techniques is refactoring which represents introducing structured changes in software in order to improve its readability, extensibility, and maintainability, while preserving behavior of the software. The main application area for refactorings is still programming code, despite the fact that modeling languages and techniques has significantly gained in popularity, in recent years. The main topic of this thesis is making an alliance between the two virtually orthogonal techniques: software modeling and refactoring. In this thesis we have investigated how to raise the level of abstraction of programming code refactorings to the modeling level. This resulted in a catalog of model refactorings each specified as a model transformation rule. In addition, we have investigated synchronization problems between different models used to describe one software system, i.e. when one model is refactored what is the impact on all dependent models and how this impact can be formalized. We have concentrated on UML class diagrams as domain of refactorings. As models dependent on class diagrams, we have selected Object Constraint Language (OCL) annotations, and object diagrams. This thesis formalizes the most important refactoring rules for UML class diagrams and classifies them with respect to their impact on object diagrams and annotated OCL constraints. For refactoring rules that have an impact on dependent artifacts we formalize the necessary changes of these artifacts. Moreover, in this thesis, we present a simple criterion and a proof technique for the semantic preservation of refactoring rules that are defined for UML class and object diagrams, and OCL constraints. In order to be able to prove semantic preservation, we propose a model transformation approach to specify the semantics of constraint languages.

EPFL2008

An Ontology-Based Approach for Closed-Loop Product Lifecycle Management

Aristeidis Matsokis

EPFL2010

Model refactoring using transformations

Slavisa Markovic

EPFL2008

An Ontology-Based Approach for Closed-Loop Product Lifecycle Management

S²E: A Platform for In-Vivo Multi-Path Analysis of Software Systems

Model refactoring using transformations

An Ontology-Based Approach for Closed-Loop Product Lifecycle Management

S²E: A Platform for In-Vivo Multi-Path Analysis of Software Systems

Model refactoring using transformations