On the engineering of crucial software

The various aspects of the conventional software development cycle are examined. This cycle was the basis of the augmented approach contained in the original grant proposal. This cycle was found inadequate for crucial software development, and the justification for this opinion is presented. Several possible enhancements to the conventional software cycle are discussed. Software fault tolerance, a possible enhancement of major importance, is discussed separately. Formal verification using mathematical proof is considered. Automatic programming is a radical alternative to the conventional cycle and is discussed. Recommendations for a comprehensive approach are presented, and various experiments which could be conducted in AIRLAB are described

MAX: a mechatronic model building environment

Abstract: A description is given of the state of the art and the functionality of MAX, an expert system for supporting conceptual design of mechatronic systems. Three model building principles are combined in MAX: – embedding equations in networks: a tight coupling between the graphical model formulation and the underlying equations assists the user in model building and evaluation. – multiple model formulations: one system can be manipulated and inspected simultaneously in multiple formulations (languages). – polymorphic modelling: a submodel definition is divided into a type that defines essential properties, and a specification that defines incidental properties. One type generally has multiple specifications, and types are organised hierarchically inside the library. By means of a simple case study, the utility of these principles is demonstrated. It is shown that MAX is a powerful model building environment that is well adapted to usage by designers.

Structured representation for requirements and specifications

This document was generated in support of NASA contract NAS1-18586, Design and Validation of Digital Flight Control Systems suitable for Fly-By-Wire Applications, Task Assignment 2. Task 2 is associated with a formal representation of requirements and specifications. In particular, this document contains results associated with the development of a Wide-Spectrum Requirements Specification Language (WSRSL) that can be used to express system requirements and specifications in both stylized and formal forms. Included with this development are prototype tools to support the specification language. In addition a preliminary requirements specification methodology based on the WSRSL has been developed. Lastly, the methodology has been applied to an Advanced Subsonic Civil Transport Flight Control System

GRASP/Ada (Graphical Representations of Algorithms, Structures, and Processes for Ada): The development of a program analysis environment for Ada. Reverse engineering tools for Ada, task 1, phase 2

The study, formulation, and generation of structures for Ada (GRASP/Ada) are discussed in this second phase report of a three phase effort. Various graphical representations that can be extracted or generated from source code are described and categorized with focus on reverse engineering. The overall goal is to provide the foundation for a CASE (computer-aided software design) environment in which reverse engineering and forward engineering (development) are tightly coupled. Emphasis is on a subset of architectural diagrams that can be generated automatically from source code with the control structure diagram (CSD) included for completeness

Java operating systems: design and implementation

Journal ArticleLanguage-based extensible systems such as Java use type safety to provide memory safety in a single address space. Memory safety alone, however, is not sufficient to protect different applications from each other. such systems must support a process model that enables the control and management of computational resources. In particular, language-based extensible systems must support resource control mechanisms analogous to those in standard operating-systems. They must support the separation of processes and limit their use of resources, but still support safe and efficient interprocess communication

Component technology - what, where, and how?

Software components, if used properly, ofj~r many software engineering benefits. Yet, they also pose many original challenges starting fi'om quality assurance and ranging to architectural embedding and composability. In addition, the recent movement towards ervices, as well as the established world of objects, causes many to wonder what purpose components might have. This extended abstract summarizes the main points of my Frontiers of Software Practice (FOSP) talk at ICSE 2003. The topics covered aim to offbr an end-to-end overview of what role components shouM play, where they should be used, and how this can be achieved Some key open problems are also pointed out

Considerations for a design and operations knowledge support system for Space Station Freedom

Engineering and operations of modern engineered systems depend critically upon detailed design and operations knowledge that is accurate and authoritative. A design and operations knowledge support system (DOKSS) is a modern computer-based information system providing knowledge about the creation, evolution, and growth of an engineered system. The purpose of a DOKSS is to provide convenient and effective access to this multifaceted information. The complexity of Space Station Freedom's (SSF's) systems, elements, interfaces, and organizations makes convenient access to design knowledge especially important, when compared to simpler systems. The life cycle length, being 30 or more years, adds a new dimension to space operations, maintenance, and evolution. Provided here is a review and discussion of design knowledge support systems to be delivered and operated as a critical part of the engineered system. A concept of a DOKSS for Space Station Freedom (SSF) is presented. This is followed by a detailed discussion of a DOKSS for the Lyndon B. Johnson Space Center and Work Package-2 portions of SSF

Land information systems : an overview and outline of software requirements

This thesis looks at some aspects of land information systems. The introduction gives the rationale for this study, and the second chapter outlines the development of land information systems with particular reference to the cadastre. In the third chapter the software requirements for the development of land information systems are considered. Programming language and databases are discussed. The fouth chapter deals with the organisation and hardware needed for a land information system. Finally, in the fifth chapter some of the algorithms used in land information systems are presented. Four appendices cover the programmes which were developed in the course of this study, the software specification for an operational system, an example of LIS-related data in a large organisation, and the syntax of Modula-2, the programming language used for the examples