Integrating legacy mainframe systems: architectural issues and solutions

For more than 30 years, mainframe computers have been the backbone of computing systems throughout the world. Even today it is estimated that some 80% of the worlds' data is held on such machines. However, new business requirements and pressure from evolving technologies, such as the Internet is pushing these existing systems to their limits and they are reaching breaking point. The Banking and Financial Sectors in particular have been relying on mainframes for the longest time to do their business and as a result it is they that feel these pressures the most. In recent years there have been various solutions for enabling a re-engineering of these legacy systems. It quickly became clear that to completely rewrite them was not possible so various integration strategies emerged. Out of these new integration strategies, the CORBA standard by the Object Management Group emerged as the strongest, providing a standards based solution that enabled the mainframe applications become a peer in a distributed computing environment. However, the requirements did not stop there. The mainframe systems were reliable, secure, scalable and fast, so any integration strategy had to ensure that the new distributed systems did not lose any of these benefits. Various patterns or general solutions to the problem of meeting these requirements have arisen and this research looks at applying some of these patterns to mainframe based CORBA applications. The purpose of this research is to examine some of the issues involved with making mainframebased legacy applications inter-operate with newer Object Oriented Technologies

To Host a Legacy System to the Web

The dramatic improvements in global interconectivity due to intranets, extranets and the Internet has led to many enterprises to consider migrating legacy systems to a web based systems. While data remapping is relatively straightforward in most cases, greater challenges lie in adapting legacy application software. This research effort describes an experiment in which a legacy system is migrated to a web-client/server environment. First, this thesis reports on the difficulties and issues arising when porting a legacy system International Invoice (IIMM) to a web-client/server environment. Next, this research analyzes the underlying issues, and offer cautionary guidance to future migrators and finally this research effort builds a prototype of the legacy system on a web client/server environment that demonstrates effective strategies to deal with these issues

High Availability and Scalability of Mainframe Environments using System z and z/OS as example

Mainframe computers are the backbone of industrial and commercial computing, hosting the most relevant and critical data of businesses. One of the most important mainframe environments is IBM System z with the operating system z/OS. This book introduces mainframe technology of System z and z/OS with respect to high availability and scalability. It highlights their presence on different levels within the hardware and software stack to satisfy the needs for large IT organizations

Web services strategy

Thesis (S.M.M.O.T.)--Massachusetts Institute of Technology, Sloan School of Management, Management of Technology Program, 2003.June 2003.Includes bibliographical references (p. 116-123).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Everything is connected to everything. El Aleph (1945), by Jorge Luis Borges[1] This thesis addresses the need to simplify and streamline web service network infrastructure and to identify business models that best leverage Web services technology and industry dynamics to generate positive business results. Web services have evolved from the simple page-display protocol of their origin and now reach beyond the links that simply updated web data dynamically from corporate databases, to where systems can automatically transact. These Web services represent a series of network business technology standards and capabilities that irrevocably change the way in which businesses will do business. In fact, every business today is a networked business and has opportunities to grow using Web services. This study focuses on the implementation challenges in the financial services market, specifically the On Line Transaction Processing (OLTP) sector where legacy mainframes interface with multiple tiers of distribution through proprietary EDI links. The OLTP industry operates under stringent regulatory requirements for availability and audit-ability of not only who performed what transaction, but who had access to the information about the information. In this environment organizational demands on network infrastructure including hardware, software and personnel are changing radically, while concurrently Information Technology (IT) budgets are under pressure. The strategic choices for deploying web services in this environment may contain lessons for other industries where cost effective large scale processing, high availability, security, manageability and Intellectual Property Rights (IPR) are paramount concerns. In this paper we use a systems dynamics model to simulate the impact of market changes on the adoption of innovative technologies and their commoditization on the industry value chain, with the aim of identifying business models and network topologies which best support the growth of an Open Systems network business. From the results of the simulation we will derive strategic recommendations for networked business models and web services integration strategies to meet Line Of Business (LOB) objectives.by Stephen B. Miles.S.M.M.O.T

Enterprise Computing: Band 1Einführung in z/OS: Band 2z/OS Internet Integration: Band 3Praktische Übungen unter z/OS

Das vorliegende Buch entstand aus einer zweisemestrigen Vorlesung „Enterprise Computing“, die wir gemeinsam über viele Jahre als Teil des Bachelor- oder Master-Studienganges an der Universität Leipzig gehalten haben. Das Buch führt ein in die Welt des Mainframe und soll dem Leser einen einführenden Überblick geben. Band 1 ist der Einführung in z/OS gewidmet, während sich Band 2 mit der Internet Integration beschäftigt. Ergänzend werden in Band 3 praktische Übungen unter z/OS dargestellt

Design Information Recovery from Legacy System COBOL Source Code: Research on a Reverse Engineering Methodology

Much of the software in the world today was developed from the mid-1960s to the mid- 1970s.This legacy software deteriorates as it is modified to satisfy new organizational requirements. Currently, legacy system maintenance requires more time than new system development. Eventually, legacy systems must be replaced. Identifying their functionality is a critical part of the replacement effort. Recovering functions from source code is difficult because the domain knowledge used to develop the system is not routinely retained. The source code is frequently the only reliable source of functional information. This dissertation describes functional process information recovery from COBOL source code in the military logistics system domain. The methodology was developed as an information processing application. Conceptual and logical models to convert source code to functional design information were created to define the process. A supporting data structure was also developed. The process reverse engineering methodology was manually applied to a test case to demonstrate feasibility, practicality, and usefulness. Metrics for predicting the time required were developed and analyzed based on the results of the test case. The methodology was found to be effective in recovering functional process information from source code. A prototype program information database was developed and implemented to aid in data collection and manipulation; it also supported the process of preparing program structure models. Recommendations for further research include applying the methodology. to a larger test case to validate findings and extending it to include a comparable data reverse engineering procedure

The Software Continuum Concept: Towards a Biologically Inspired Model for Robust E-Business Software Automation

This paper introduces a new concept, the software continuum concept based on the observation that exists a general parallelism between the software continuum from bits to business/Internet ecosystems and the natural continuum from particles to ecosystems. The general parallelism suggests that homeomorphisms may be identified and therefore some concepts, processes, and/or mechanisms in one continuum can be investigated for application in the other continuum. We argue that the homeomorphisms give rise to a biologically-inspired architectural framework for addressing robust control, robust intelligence, and robust autonomy issues in e-business software and other business-IT integration challenges. As application, we examine the mapping of a major enterprise-level architecture framework to the biologically-inspired framework. Design considerations for robust intelligence and autonomy in large-scale software automation and some major systemic features for flexible business-IT integration are also discussed