Digital Government Systems: Tackling The Legacy Problem Through A Game-Based Approach To Business Requirements Analysis

Government agency reliance on legacy systems is problematic: they are costly to maintain, difficult to integrate with and they hinder innovation. However, the replacement of legacy systems is not a straightforward endeavor, and it often results in technology substitution that is not accompanied by business process change. The focus of this dissertation is on the phenomenon of legacy system replication wherein the requirements for applications replacing outdated technologies mimic legacy features and reflect status quo operational processes that have been historically shaped by the legacy system itself. This problem is referred to throughout the dissertation as the “legacy problem.” The dissertation investigates its roots and proposes an approach to overcome it. Specifically, a mixed method research approach is taken, including a survey of public sector practitioners to explore the extent of the legacy problem, and a series of semi-structured interviews with government information technology and management professionals to delve into the dynamics of legacy system replacement projects. Findings indicate that the legacy problem often stems from a lack of critical analysis of business requirements and the desire to minimize the risks associated with organizational change, which often result in missed opportunities for digital government innovation. As a consequence, the dissertation proposes a candidate approach to deal with the legacy problem in the development of a requirements game (RE-PROVO) which supports requirements discussions structured around the themes of legacy (or heritage) preservation and innovation. The game is evaluated by local government practitioners through several iterations and their feedback is analysed to gauge the potential utility of the approach. The results indicate that with a streamlined user interface and accentuated game elements RE-PROVO can be a valuable and effective tool for requirements analysis in legacy system replacement projects

A formal framework for specification-based embedded real-time system engineering

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2008.Includes bibliographical references (v. 2, p. 517-545).The increasing size and complexity of modern software-intensive systems present novel challenges when engineering high-integrity artifacts within aggressive budgetary constraints. Among these challenges, ensuring confidence in the engineered system, through validation and verification activities, represents the high cost item on many projects. The expensive nature of engineering high-integrity systems using traditional approaches can be partly attributed to the lack of analysis facilities during the early phases of the lifecycle, causing the validation and verification activities to begin too late in the engineering lifecycle. Other challenges include the management of complexity, opportunities for reuse without compromising confidence, and the ability to trace system features across lifecycle phases. The use of models as a specification mechanism provides an approach to mitigate complexity through abstraction. Furthermore, if the specification approach has formal underpinnings, the use of models can be leveraged to automate engineering activities such as formal analysis and test case generation. The research presented in this thesis proposes an engineering framework which addresses the high cost of validation and verification activities through specification-based system engineering. More specifically, the framework provides an integrated approach to embedded real-time system engineering which incorporates specification, simulation, formal verification, and test-case generation. The framework aggregates the state-of-the-art in individual software engineering disciplines to provide an end-to-end approach to embedded real-time system engineering. The key aspects of the framework include: * A novel specification language, the Timed Abstract State Machine (TASM) language, which extends the theory of Abstract State Machines (ASM).(cont.) The TASM language is a literate formal specification language which can be applied and multiple levels of abstraction and which can express the three key aspects of embedded real-time systems - function, time, and resources. * Automated verification capabilities achieved through the integration of mature analysis engines, namely the UPPAAL tool suite and the SAT4J SAT solver. The verification capabilities provided by the framework include completeness and consistency verification, model checking, execution time analysis, and resource consumption analysis. * Bi-directional traceability of model features across levels of abstraction and lifecycle phases. Traceability is achieved syntactically through archetypical refinement types; each refinement type provides correctness criteria, which, if met, guarantee semantic integrity through the refinement. * Automated test case generation capabilities for unit testing, integration testing, and regression testing. Unit test cases are generated to achieve TASM specification coverage through the rule coverage criterion. Integration test case generation is achieved through the hierarchical composition of unit test cases. Regression test case generation is achieved by leveraging the bi-directional traceability of model features. The framework is implemented into an integrated tool suite, the TASM toolset, which incorporates the UPPAAL tool suite and the SAT4J SAT solver. The toolset and framework are evaluated through experimentation on three industrial case studies - an automated manufacturing system, a "drive-by-wire" system used at a major automotive manufacturer, and a scripting environment used on the International Space Station.by Martin Ouimet.Ph.D