International Journal of Software Engineering and Knowledge Engineering

The definition and use of multi-valued constant propagation analysis (MVCP), which is an extension of simple constant propagation analysis, is presented in this paper in the context of a user interface reengineering process.

A brief description of the adopted COBOL/CICS user interface reengineering model, which makes use of an Abstract User Interface Description Language (AUIDL) to represent user interface structures and behavior, is also given.

The experimental context is described and results are shown and discussed. Suggestions for further directions of research and investigation are also presented.

There is a vast collection of operational software systems which are vitally important to their users, yet are becoming increasingly difficult to maintain, enhance, and keep up to date with rapidly changing requirements. For many of these so-called legacy systems, the option of throwing the system away and rewriting it from scratch is not economically viable. Methods are therefore urgently required which enable these systems to evolve in a controlled manner. The approach described in this paper uses formal proven program transformations, which preserve or refine the semantics of a program while changing its form. These transformations are applied to restructure and simplify the legacy systems and to extract higher-level representations. By using an appropriate sequence of transformations, the extracted representation is guaranteed to be equivalent to the code. The method is based on a formal wide spectrum language, called WSL, with an accompanying formal method. Over the last ten years we have developed a large catalog of proven transformations, together with mechanically verifiable applicability conditions. These have been applied to many software development, reverse engineering, and maintenance problems. In this paper, we focus on the results of using this approach in the reverse engineering of medium scale, industrial software, written mostly in languages such as assembler and JOVIAL. Results from both benchmark algorithms and heavily modified, geriatric software are summarized. We conclude that formal methods have an important practical role in software evolution.

Software evolution has no common paradigm which practitioners can adhere to. On the contrary, there is a wide range of models, methods, techniques, and tools which are selected according to the specific task, the application domain, the professional experience, and the organizational culture. We argue that different approaches and technologies may be combined into a unique platform to satisfy the needs of software systems which evolve over long periods of time.

This paper presents the Integrated Environment for Software Evolution Management (IESEM) which includes software repositories, reverse engineering tools, rationale capture tools, software measurement tools, and a user-friendly interface. It can manage heterogeneous systems characterized by various design methods and programming languages. IESEM is based on a central repository which stores software engineering artifacts, program code, design, and implementation decisions in the form of a traceability graph. The repository stores also software measures computed both from programs and external CASE repositories. Measures are used to control software degradation during its evolution and to support decisions based on quality factors.

The key concepts of IESEM, its design, and implementation are presented. The use of IESEM during development and maintenance is discussed. A case study shows IESEM's effectiveness in performing maintenance tasks.

This paper presents a pragmatic knowledge-based approach to evolving and reengineering legacy business software systems. We describe a CASE tool for assisting legacy system evolution by automating the tedious and knowledge-intensive conversion process and show how we developed and maintained the tool and how it is used with payoff. This work demonstrates that timely technology upgrades of legacy systems are only possible with carefully engineered knowledge-based tools. Viewing software as an artifact with structure, behavior, and function, we can represent most program conversion knowledge explicitly for function-preserving transformation in an automated conversion system. The payoff for using the knowledge-based approach to software evolution is not only in terms of valuable resources saved, but also in terms of improved quality of the upgraded software systems.

This paper explores the possibility of automated support for detecting inconsistencies in software systems and requirements. The inconsistencies are introduced when the environment of the software system changes. We refer to the software environment as its context. We review the recent research progress on nonmonotonic logics, pointing out the significance of these results to software maintenance. We explain how a practical implementation of such logics can be obtained via a simple extension to logic programming in the form of an answer procedure that realizes the Extended Logic Semantics [7] for nonmonotonic logic programs that have a unique answer set (which is a large and useful class of logic programs).

We augment the existing automated capabilities of the Computer-Aided Prototyping System (CAPS) for rapid prototyping via the extension to logic programming to provide an improved automated capability for detecting certain kinds of inconsistencies created by implicit requirements changes. We illustrate the significance of this capability via an example prototype for a problem originally suggested by Lehman.

This paper describes an approach to software reuse that involves generating and retrieving abstractions from existing software systems using concept formation methods. The potential of the approach is illustrated through two important activities of the reuse process. First, the concept hierarchy generated by the concept formation methods is used for organizing and retrieving the artifacts inside a repository. Second, the generated concepts are used in identifying new abstractions that may be converted into new, more generic artifacts with better reuse potential. These experiments are part of a major software engineering research project involving many business and academic partners.

Access to information using the Internet has undergone dramatic change and expansion recently. The unrivaled success of the World Wide Web has altered the Internet from something approachable only by the initiated to something of a media craze — the information superhighway made manifest in the personal "home page". This paper surveys the beginnings of network information discovery and retrieval, how the Web has created a surprising level of integration of these systems, and where the current state of the art lies in creating globally accessible information spaces and supporting access to those information spaces.