A Reengineering Approach to Reconciling Requirements and Implementation for Context - Aware Web Services Systems

In modern software development, the gap between software requirements and implementation is not always conciliated. Typically, for Web services-based context-aware systems, reconciling this gap is even harder. The aim of this research is to explore how software reengineering can facilitate the reconciliation between requirements and implementation for the said systems. The underlying research in this thesis comprises the following three components. Firstly, the requirements recovery framework underpins the requirements elicitation approach on the proposed reengineering framework. This approach consists of three stages: 1) Hypothesis generation, where a list of hypothesis source code information is generated; 2) Segmentation, where the hypothesis list is grouped into segments; 3) Concept binding, where the segments turn into a list of concept bindings linking regions of source code. Secondly, the derived viewpoints-based context-aware service requirements model is proposed to fully discover constraints, and the requirements evolution model is developed to maintain and specify the requirements evolution process for supporting context-aware services evolution. Finally, inspired by context-oriented programming concepts and approaches, ContXFS is implemented as a COP-inspired conceptual library in F#, which enables developers to facilitate dynamic context adaption. This library along with context-aware requirements analyses mitigate the development of the said systems to a great extent, which in turn, achieves reconciliation between requirements and implementation

Reengineering using a data abstraction based specification language

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1992.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaves 86-88).by Randall E. Duran.M.S

Extraction of objects from legacy systems: an example using cobol legacy systems

In the last few years the interest in legacy information system has increased because of the escalating resources spent on their maintenance. On the other hand, the importance of extracting knowledge from business rules is becoming a crucial issue for modern business: sometime, because of inappropriate documentation, this knowledge is essentially only stored in the code. A way to improve their use and maintainability in the present environment is to migrate them into a new hardware / software platform reusing as much of their experience as possible during this process. This migration process promotes the population of a repository of reusable software components for their reuse in the development of a new system in that application domain or in the later maintenance processes. The actual trend in the migration of a legacy information system, is to exploit the potentialities of object oriented technology as a natural extension of earlier structured programming techniques. This is done by decomposing the program into several agent-like modules communicating via message passing, and providing to this system some object oriented key features. The key step is the "object isolation", i.e. the isolation of .groups of routines and related data items : to candidates in order to implement an abstraction in the application domain. The main idea of the object isolation method presented here is to extract information from the data flow, to cluster all the procedures on the base of their data accesses. It will examine "how" a procedure accesses the data in order to distinguish several types of accesses and to permit a better understanding of the functionality of the candidate objects. These candidate modules support the population of a repository of reusable software components that might be used as a basis of the process of evolution leading to a new object oriented system reusing the extracted objects

MetNetAPI: A flexible method to access and manipulate biological network data from MetNet

<p>Abstract</p> <p>Background</p> <p>Convenient programmatic access to different biological databases allows automated integration of scientific knowledge. Many databases support a function to download files or data snapshots, or a webservice that offers "live" data. However, the functionality that a database offers cannot be represented in a static data download file, and webservices may consume considerable computational resources from the host server.</p> <p>Results</p> <p>MetNetAPI is a versatile Application Programming Interface (API) to the MetNetDB database. It abstracts, captures and retains operations away from a biological network repository and website. A range of database functions, previously only available online, can be immediately (and independently from the website) applied to a dataset of interest. Data is available in four layers: molecular entities, localized entities (linked to a specific organelle), interactions, and pathways. Navigation between these layers is intuitive (e.g. one can request the molecular entities in a pathway, as well as request in what pathways a specific entity participates). Data retrieval can be customized: Network objects allow the construction of new and integration of existing pathways and interactions, which can be uploaded back to our server. In contrast to webservices, the computational demand on the host server is limited to processing data-related queries only.</p> <p>Conclusions</p> <p>An API provides several advantages to a systems biology software platform. MetNetAPI illustrates an interface with a central repository of data that represents the complex interrelationships of a metabolic and regulatory network. As an alternative to data-dumps and webservices, it allows access to a current and "live" database and exposes analytical functions to application developers. Yet it only requires limited resources on the server-side (thin server/fat client setup). The API is available for Java, Microsoft.NET and R programming environments and offers flexible query and broad data- retrieval methods. Data retrieval can be customized to client needs and the API offers a framework to construct and manipulate user-defined networks. The design principles can be used as a template to build programmable interfaces for other biological databases. The API software and tutorials are available at <url>http://www.metnetonline.org/api</url>.</p

A method for maintaining new software

This thesis describes a novel method for perfective maintenance of software which has been developed from specifications using formal transformations. The list of applied transformations provides a suitable derivation history to use when changes are made to the software. The method uses transformations which have been implemented in a tool called the Maintainer's Assistant for the purposes of restructuring code. The method uses these transformations for refinement. Comparisons are made between sequential transformations, refinement calculi and standard proof based refinement techniques for providing a suitable derivation history to use when changes are made in the requirements of a system. Two case studies are presented upon which these comparisons are based and on which the method is tested. Criteria such as saleability, speed, ease, design improvements and software quality is used to argue that transformations are a more favourable basis of refinement. Metrics are used to evaluate the complexity of the code developed using the method. Conclusions of how to develop different types of specifications into code and on how best to apply various changes are presented. An approach which is recommended is to use transformations for splitting the specification so that original refinement paths can still be used. Using transformations for refining a specification and recording this path produces software of a better structure and of higher maintainability. Having such a path improves the speed and ease of future alterations to the system. This is more cost effective than redeveloping the software from a new specification

Database Migration: A Literature Review and Case Study

This literature review provides an overview of various areas of research in database migration. Specific areas which are addressed are legacy migration, migrating between different database models, reverse engineering, schema design and translation, and security. Additional literature is considered which provides a general overview of the topic. Some case study literature is included with an emphasis on library science studies. This literature review is then applied to a case study migration project at the University of North Carolina at Chapel Hill in order to determine where the literature was helpful and where not, as well as where more research may be needed. Conclusions are drawn that the theoretical literature is quite comprehensive, but that literature having more practical application could certainly be strengthened

Development of a model for the migration of legacy architectures

Diese Arbeit beschäftigt sich mit der Erstellung eines holistischen Modells für Migrationen von Alt(last)systemen in der IT. Dafür ist es notwendig zuerst festzustellen was sogenannte Legacy Systeme überhaupt ausmacht und welche Probleme diese mit sich bringen. Danach werden bestehende Migrationsarten und -vorgehensweisen erörtert und aufgezeigt welche Architekturen und Trends momentan auf dem Markt vorhanden sind. Um die im letzten Abschnitt der Arbeit vorgeschlagene Migrationsstrategie zu unterstützen werden Methoden zur Risikokontrolle, zur Einbeziehung von Stakeholdern und zur wirtschaftlichen Begründbarkeit eingeführt. Schließlich werden der Referenzprozess ReMiP und TOGAF als Framework für Enterprise Architecture vorgestellt und eine Kombination der beiden vorgeschlagen und in einem Referenzmodell beschrieben. Die erwarteten Vorteile durch die in dieser Arbeit diskutierte kombinierte Anwendung werden von einem externen Experten aus dem Arbeitsfeld von IT Migrationen nach ihrer Anwendbarkeit beurteilt.This paper is proposing a holistic process model for the migration of legacy infrastructures. To achieve this objective it is therefore necessary to investigate and define what legacy architectures and their related problems are. After that the established migration approaches to address the legacy challenge and an overview of current and ongoing architectures and trends form a broad enough headstone to then go on discussing which methodologies and means are available to facilitate a smooth migration. These are spanning from the human factor via risk control to economic matters related to system transformation projects. Finally the migration reference process ReMiP and the enterprise architecture framework TOGAF are introduced and combined to consolidate the presented approaches. The closing chapters compare the expected benefits with the requirements of a practitioner, propose a reference migration model and finally summarise the proposed approach

Migration from Legacy to Reactive Applications in OutSystems

A legacy system is an information system that significantly resists evolution. Through a migration, these systems can be moved to a more modernized environment without having to be redeveloped. OutSystems is a software company with a platform to develop and maintain applications using abstraction to increase productivity. In October 2019, OutSystems launched a new paradigm to allow developers to build reactive web applications. Because of this, the applications implemented in the old web paradigm turned into legacy systems. The OutSystems’ approach to this problem was a manual migration. However, it discards a considerable part of the effort previously made on the legacy system. A well-founded case study took place and allowed us to classify the UI as the most prioritized feature, but coincidently, the major bottleneck in migrations. So, this project had the following objectives: (1) The design and implementation of an automatic migration approach capable of converting UI elements to accelerate the manual migration; (2) The integration of the developed tool in the OutSystems platform. To transform the OutSystems paradigm’s elements, model-driven transformation rules must be set to receive the source UI elements and produce the target equivalent implementation in the new paradigm (each according to their model). However, the trans formations may not be straightforward, and a set of elements may need to be migrated to a different implementation due to Reactive Web’s best practices. Via the creation and search of UI patterns, it is possible to make special transformations for such scenarios. As a result, a migration approach was developed, allowing for the migration of UI (and other) elements. To complement this objective, the developed tool was integrated into the OutSystems platform with an easy to use interaction. Performance and usability tests proved the necessity and impact the final result had on the migration problem. This dissertation’s objectives were fully met and even exceeded, accelerating the man ual migration by providing an automatic UI conversion. This provided a quality increase in the existing process and results, giving OutSystems and its users the possibility of evolving their applications with considerable less effort and investment.Um sistema legado é um sistema de informação que resiste à evolução. Através de uma migração, estes sistemas podem ser movidos para um ambiente modernizado sem necessitar de re-implementação. A OutSystems é uma empresa de software com uma plataforma para desenvolver e manter aplicações usando abstracção para aumentar a produtividade. Em Outubro de 2019, a OutSystems lançou um novo paradigma para desenvolver aplicações reactive web. Assim, as aplicações implementadas no antigo paradigma web tornaram-se sistemas legados. A abordagem da OutSystems ao problema foi uma migração manual, no entanto, esta abordagem desconsidera uma parte significativa do investimento feito no sistema legado. Uma análise permitiu classificar a UI como a característica mais priorizada, mas também como o maior obstáculo em migrações. Assim, este projecto tem como objectivos: (1) O desenho e implementação de uma migração automática capaz de converter os elementos de UI para acelerar a migração manual; (2) A integração da ferramenta desenvolvida na plataforma da OutSystems. Para transformar os elementos dos paradigmas OutSystems, transformações de modelos têm de ser definidas para receber os elementos UI e produzir a implementação equivalente no novo paradigma (de acordo com o seu modelo). No entanto, as transformações podem não ser lineares, e um conjunto de elementos pode necessitar de uma migração para uma implementação diferente devido ao Reactive Web. Com a definição e procura de padrões de UI, é possível fazer transformações especiais para esses cenários. Como resultado, a migração foi desenvolvida, permitindo a conversão de elementos de UI (e não só). Para complementar, a ferramenta desenvolvida foi integrada na plataforma da OutSystems com uma interacção de fácil uso. Testes de desempenho e usabilidade provaram a necessidade e impacto da ferramenta no contexto da migração manual. Os objectivos desta dissertação foram completados na totalidade, acelerando a migração manual com a automação da migração de UI. Isto traz um aumento da qualidade no processo existente e nos seus resultados, dando à OutSystems e aos seus utilizadores a possibilidade de evoluírem as suas aplicações com um esforço e investimento menores

A program slicing method for a wide spectrum language

This thesis describes the implementation of a program slicer for WSL - a Wide Spectrum Language - which is a language that allows different levels of abstraction to coexist in the same program. WSL contains constructs not found in conventional languages, e.g. action systems (which model a segment of code with GOTOs and labels) and non deterministic constructs. Program slicing is a method for restricting a program to a specified behaviour of interest. Usually this behaviour of interest is expressed in terms of a variable or a set of variables. The method used in the thesis to slice a program is different from the classical ones in that slices do not need to be computed from an output statement, and in that slices are computed on a wide spectrum language closer to a functional language, instead of being computed on a more conventional, procedural language. A slicer for a subset of WSL has been designed and implemented based on the data flow analysis techniques for while-programs of Bergeretti and Carré [10]. It has been necessary to modify the algorithm to permit incremental slicing. Modifications of their algorithm were also needed to accommodate the specific WSL constructs mentioned above. The implementation has been developed using a rapid prototyping approach. The prototype has provided new ideas and enhancements for a more comprehensive sheer which could be implemented in the future. The slicer has assisted the maintainer using ReForm - a reverse engineering project developed at Durham University - in understanding and debugging a program by decomposing it. At the end of this thesis results showing how slicing has helped the maintainer are presented. Conclusions on the method used, the validity of the tool, and its engineering are also summarized