Managing Change in Information Systems : technological challenges

Information systems and other computer-based systems must continuously undergo change in order to reflect change in their environments. The present technology used to implement such systems, including models, methods, tools and languages, does not have an inherent understanding of the nature of evolution. The rigidity of existing systems is a hindrance for user requested enhancements.Propagating changes correctly is a particular problem. It is common to find that necessary changes consequent on some other change have not been made, so that the system is inconsistent and will eventually fail to operate correctly. The paper discusses tools for system maintenance and focuses on the issue of automation. A tool that automatically generates and maintains all the information it needs is presented. To provide more information about the form and extent of the evolution in real-world systems, the same tool was instructed to collect change measurements. Information about the evolution of a large health management system was recorded over a period of 18 months. Methods for and problems of automatic change measurements collection are discussed

Capture and Maintenance of Constraints in Engineering Design

The thesis investigates two domains, initially the kite domain and then part of a more demanding Rolls-Royce domain (jet engine design). Four main types of refinement rules that use the associated application conditions and domain ontology to support the maintenance of constraints are proposed. The refinement rules have been implemented in ConEditor and the extended system is known as ConEditor+. With the help of ConEditor+, the thesis demonstrates that an explicit representation of application conditions together with the corresponding constraints and the domain ontology can be used to detect inconsistencies, redundancy, subsumption and fusion, reduce the number of spurious inconsistencies and prevent the identification of inappropriate refinements of redundancy, subsumption and fusion between pairs of constraints.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Recommendations for Evolving Relational Databases

International audienceRelational databases play a central role in many information systems. Their schemas contain structural and behavioral entity descriptions. Databases must continuously be adapted to new requirements of a world in constant change while: (1) relational database management systems (RDBMS) do not allow inconsistencies in the schema; (2) stored procedure bodies are not meta-described in RDBMS such as PostgreSQL that consider their bodies as plain text. As a consequence , evaluating the impact of an evolution of the database schema is cumbersome , being essentially manual. We present a semi-automatic approach based on recommendations that can be compiled into a SQL patch fulfilling RDBMS constraints. To support recommendations, we designed a meta-model for relational databases easing computation of change impact. We performed an experiment to validate the approach by reproducing a real evolution on a database. The results of our experiment show that our approach can set the database in the same state as the one produced by the manual evolution in 75% less time