Legacy system migration: A legacy data migration engine

1997

Legacy information systems typically form the backbone of the information flow within an organisation and are the main vehicle for consolidating information about the business. As a solution to the problems these systems posebrittleness, inflexibility, isolation, non-extensibility, lack of openness etc. -many companies are migrating their legacy systems to new environments which allow the information system to more easily adapt to new business requirements. This paper presents a survey of research into Migration of Legacy Information Systems. The main problems that companies with legacy systems must face are analysed, and the challenges possible solutions must solve discussed. The paper provides an overview of the most important currently available solutions, and their main downsides are

Springer eBooks, 2008

This chapter addresses the problem of platform migration of large business applications, that is, complex software systems built around a database and comprising thousands of programs. More specifically, it studies the substitution of a modern data management technology for a legacy one. Platform migration raises two major issues. The first one is the conversion of the database to a new data management paradigm. Recent results have shown that automated lossless database migration can be achieved, both at the schema and data levels. The second problem concerns the adaptation of the application programs to the migrated database schema and to the target data management system. This chapter first poses the problem and describes the State of the Art in information system migration. Then, it develops a two-dimensional reference framework that identifies six representative migration strategies. The latter are further analyzed in order to identify methodological requirements. In particular, it appears that transformational techniques are particularly suited to drive the whole migration process. We describe the database migration process, which is a variant of database reengineering. Then, the problem of program conversion is studied. Some migration strategies appear to minimize the program understanding effort, and therefore are sound candidates to develop practical methodologies. Finally, the chapter describes a tool that supports such methodologies and discusses some real-size case studies.

The widespread use of computer technology over several decades has resulted in some large, complex systems that have evolved to a state where they significantly resist further modification and evolution. Although these Legacy Information Systems pose considerable problems (brittleness, inflexibility, isolation, non-extensibility, lack of openness, etc.), they may also be mission-critical: if one of these systems stops working the business may grind to a halt. Thus for many organisations, decommissioning is not an option. An alternative solution is Legacy System Migration that has recently become an important research and practical issue. Legacy System Migration is a relatively new field of research and few comprehensive methods or practical experiences have been reported. This paper provides a brief overview of existing research and practise when dealing with Legacy Information Systems, and in particular of the area of Legacy Information System Migration.

… , 1997. Asia Pacific... …, 1997

The problems posed by mission-critical legacy systems -brittleness, inflexibility, isolation, non-extensibility, lack of openness etc. -are well known, but practical solutions have been slow to emerge. Most approaches are "ad hoc" and tailored to peculiarities of individual systems. This paper presents an approach to mission-critical legacy system migration : the Butterfly Methodology, its data migration engine and supporting tool-kit framework. Data migration is the primary focus of the Butterfly methodology, however, it is placed in the overall context of a complete legacy system migration. The fundamental premise of the Butterfly methodology is to question the need for parallel operation of the legacy and target systems during migration. Much of the complexity of the current migration methodologies is eliminated by removing this interoperation assumption.

International journal of engineering research and technology, 2017

The Modernization of Legacy System is made appealing by several features of SOA in today’s world and migration of applications to the Cloud. In order to carry out a comparative review on the decades old migration approaches are classified in to Early Migration Approaches, SOA Migration Approaches and Cloud Migration. A comparative review is presented among this categories to depict the migration requirements. This paper also provides the research opportunities in the context of migration of legacy systems focusing on Legacy System Understanding, Study of Artefacts and their Relationships. Keywords— Migration; SOA; Legacy Systems; Software Evolution

2007 IEEE International Conference on Software Maintenance, 2007

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Every type of system may replace or enhance the functionality currently delivered by legacy systems to new system, regardless of the type of project/application; some data conversion may take place. Difficulties arise when we take the information currently maintained by the legacy system and transform it to fit into the new system. We refer to this process as data migration. Data migration is a common element among most system implementations. It can be performed once, as with a legacy system redesign, or may be an ongoing process as in storage of historical data in the form of a data warehouse. Some legacy system migrations require ongoing data conversion if the incoming data requires continuous cleansing. It should be that any two systems that maintain the same sort of data must be doing very similar things and, therefore, should map from one to another with ease. Legacy systems have historically proven to be far too lenient with respect to enforcing integrity at the atomic level of data. Another common problem has to do with the theoretical design differences between hierarchical and relational systems. In data migration one method apply in twice (i.e. automated and manual). This paper explores the steps to migrate date in form of manual, i.e. process of data migration without the help of any special tool those made for data migration. Manual data cleaning is commonly performed in migration to improve data quality, eliminate redundant or obsolete information, and match the requirements of the new system in correct and efficient form.

Software: Practice and Experience, 2008

This paper presents the research results of an ongoing technology transfer project carried out in cooperation between the University of Salerno and a small software company. The project is aimed at developing and transferring migration technology to the industrial partner. The partner should be enabled to migrate monolithic multi-user COBOL legacy systems to a multi-tier Web-based architecture. The assessment of the legacy systems of the partner company revealed that these systems had a very low level of decomposability with spaghetti-like code and embedded control flow and database accesses within the user interface descriptions. For this reason, it was decided to adopt an incremental migration strategy based on the reengineering of the user interface using Web technology, on the transformation of interactive legacy programs into batch programs, and the wrapping of the legacy programs. A middleware framework links the new Web-based user interface with the Wrapped Legacy System. An Eclipse plug-in, named MELIS (migration environment for legacy information systems), was also developed to support the migration process. Both the migration strategy and the tool have been applied to two essential subsystems of the most business critical legacy system of the partner company.

… Group, Technical Report TR-0222-10-92- …, 1993

1994

As is painfully evident today, the deterioration of the transportation, education 2 , and other national infrastructures negatively impacts many aspects of life, business, and our economy. This has resulted, in part, when responses to short term crises discourage investing in infrastructure enhancement and when there are no effective means for infrastructure evolution. This paper responds to the deterioration of the information system (IS) infrastructure that has strong negative impacts on ISs, on the organizations they support, and, ultimately, on the economy. This paper addresses the problem of legacy IS migration by methods that mediate between short term crises and long term goals. It presents an effective strategy and a spectrum of supporting methods for migrating legacy ISs into a target environment that includes rightsized hardware and modern technologies (i.e., infrastructure) such as a client-server architecture, DBMSs and CASE. We illustrate the methods with two migration case studies of multi-million dollar, mission critical legacy ISs. The contribution of this paper is a highly flexible set of migration methods that is tailorable to most legacy ISs and business contexts. The goal is to support continuous, iterative evolution. The critical success factor, and challenge in deployment, is to identify appropriate portions of the IS and the associated planning and management to achieve an incremental migration that is feasible with respect to the technical and business requirements. The paper concludes with a list of desirable migration tools for which basic research is required. The principles described in this paper can be used to design future ISs and an infrastructure that will support continuous IS evolution to avoid future legacy ISs.