A dual-spiral reengineering model for legacy system

A book chapter in Encyclopedia of Information Science and Technology, Fifth Edition, edited by Mehdi Khosrow-Pour D.B.A., IGI Global, 2021, pp. 1214-1230., 2021

Software reengineering is an important area of the software engineering. The quest to maintain and understand operational legacy systems has always been a challenge for software practitioners. This chapter presents a compilation of notions and techniques covering major areas namely, reverse engineering, program understanding, software maintenance, migration and evolving. Our objective is not to create new terms, but to introduce the terms already in use with different perspectives.

This paper is an attempt to define what software reengineering is and what it has accomplished in the light of 20 years of practical application. The paper points out that reengineering is one of the many software maintenance activities, i.e. everything done with software once it has been put to use. Reengineering actions are devoted to improving the technical quality of existing software. By accepting this definition, it is possible to distinguish reengineering from other related activities performed on a software product after its first release such as reverse engineering, redocumentation, evolution and migration.

International Journal of Programming Languages and Applications, 2014

The modern business environment requires organizations to be flexible and open to change if they are to gain and retain their competitive age. Competitive business environment needs to modernize existing legacy system in to self-adaptive ones. Reengineering presents an approach to transfer a legacy system towards an evolvable system. Software reengineering is a leading system evolution technique which helps in effective cost control, quality improvements and time and risk reduction. However successful improvement of legacy system through reengineering requires portfolio analysis of legacy application around various quality and functional parameters some of which includes reliability and modularity of the functions, level of usability and maintainability as well as policy and standards of software architecture and availability of required documents. Portfolio analysis around these parameters will help to examine the legacy application on quality and functional gaps within the application [1]. In this paper we identify and measure risk factors related to quality and functional aspect of legacy system. Paper analyzes a variety of risk components related to quality and functional dimensions of legacy application. Identification and development of various metrics and important measures to compute impact value of individual risk component is also addressed. Existing quality and functional level of legacy system are considered to identify and categories risk components. The impact of various technical issues such as inconsistency between architecture of legacy and target system, unmodularised legacy system architecture, unavailability of required design documents, high degree of coupling between modules of legacy system has been covered in the paper..

International Journal of Computer …, 2012

Recent trend in systems architecture and design is componentbased. A system is designed as a set of mutually supporting components that provide the intended services. The requirements models such as business type models and use case models are often used for deriving the targeted component-based architecture. The component interfaces are derived via sequence diagrams, collaboration diagrams and context diagrams. As the business model evolves, it becomes vital that the system also needs to match the business evolution whether it involves changing business rule set or growth in volume of business transactions. Timely reengineering of systems is profitable to any organization. The systems reengineering can be conducted in a pragmatic manner via component by component or a selected set of components; it becomes manageable and cost-effective to maintain the system and to train only a smaller sample of affected users. This paper offers a methodology for system reengineering via component replacement and model-viewcontrol framework for component refinement and evolution in order to achieve a reengineered system that reflects upon the latest requirements in business domain.

International Journal of Computer Science and Information Technology, 2011

Organizations that wish to modernize their legacy systems, must adopt a financial viable evolution strategy to gratify the needs of modern business environment. There are various options available to modernize legacy system in to more contemporary system. Over the last few years' legacy system reengineering has emerged as a popular system modernization technique. The reengineering generally focuses on the increased productivity and quality of the system. However many of these efforts are often less than successful because they only concentrate on symptoms of software reengineering risk without targeting root causes of those risk. A subjective assessment (diagnosis) of software reengineering risk from different domain of legacy system is required to identify the root causes of those risks. The goal of this paper is to highlight root causes of software reengineering risk. We proposed a root cause analysis model RCause that classify root causes of software reengineering risk in to three distinctive but connected areas of interest i.e. system domain, managerial domain and technical domain. .

Today’s software development is defined by continuous evolution of software products. These products are regularly updated during their usage. In most of the cases systems grow inevitably by adding new features or by changing the system architecture due to new technologies or business plans. It is more than a decade; objects oriented paradigm is adopted as the most efficient passage to build flexible software, and promptly supported by industry. Though, the benefits of object oriented paradigm are supported by many, but its usage does not necessarily result in general, adaptable systems. These huge systems are often suffering from improper use of object oriented techniques, like inheritance and the lack of object oriented methods being regulated towards the building of families of systems instead of developing single applications. These growing technologies make the systems more difficult to maintain and improve. So, there is growing demand for reengineering of object-based systems. The main intention of this paper is to discover important research directions in the area of reengineering of object oriented legacy systems, which necessitate further attention in order to build more effective and efficient reengineering technique for these systems. The paper first discusses the state of art in reengineering of legacy system and its need. Paper also discuss the benefits of component based system over object oriented system and later outlines the techniques for reengineering of object oriented legacy system. In this paper we presented statistical analysis based on more than a decade data.

It is not uncommon to find that many of the data processing systems of today have been in operation for as many as 10 – 30 years back. Legacy systems are older software systems that remain vital to an organization. Many software systems that are still in use were developed many years using technology that are now obsolete. Re-engineering is the systematic transformation of an existing system into a new form to realize quantity improvements in operation, system capability, functionality, performance or evolveability at a lower cost. This publication explores data restructuring as the common type of reengineering and its application.

In this paper, we put forward a methodology for reengineering the architecture of a legacy software system. The proposed approach is not restricted to any specific source and target architectures, or programming language. It consists in (1) achieving a representation of the source code through its categorization and structuring, (2) transforming it into the new intended architecture, and (3) generating the code for the target platform. First, the code is categorized according to its purpose by pre-defined rules and represented as a model that is an instance of a type graph. Then, this representation is transformed into the intended target architectural paradigm using graph transformation techniques. The generation of the target code is not covered in this report but will be studied in the near future. The approach attempts to address problems that are repeatedly encountered in legacy reengineering industry projects.

Science of Computer Programming, 2006

Software analysis, evolution, and reengineering are important areas of the software life cycle. The quest to maintain and keep operational large mission critical systems has always been a challenge for software practitioners. This special issue presents a compilation of papers covering six major areas namely, program understanding, tools and environments, source code modeling, component recovery, migration to network-centric platforms, and binary reverse engineering and reengineering. These papers are re-worked and extended versions of papers that appeared in the Working Conference on Reverse Engineering. We hope that the readers will find this collection of papers useful as it provides an indicative view of the current work in the areas of software analysis, evolution, and reengineering.

Ahmed Saleem Abbas, W. Jeberson & V.V. Klinsega, 2013

Software re-engineering, is a recent research area which includes reverse engineering, forward engineering and reengineering. In this paper, the software reengineering process model proposed by the same authors in another paper titled “Proposed Software Re-engineering Process That Combine Traditional Software Re-engineering Process with Spiral Model” [1] is validated by implementing it on a legacy system, and its name is renamed as FUSION model. This new model incorporates both the reverse engineering process and forward engineering process integrated with spiral model where reverse engineering applies to existing system code to extract design & requirements, although this is often used as means to mitigate risks & reduce operation and maintenance cost of the software system. This paper briefly describes the FUSION model which can be used to simplify the complex tasks. The paper represents how the legacy supermarket management system can be re-engineered using the new approach then the result of comparison between the legacy software and the re-engineered software will be presented. The features of the FUSION model are also presented in later section of the paper.