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This chapter presents the following content: Foundations of systems development, structured development, fourth-generation languages, software prototyping, computer-aided software engineering (case), object-oriented development, client-server computing.
Technologies for Developing Systems Lecture 21 Technologies for Developing Systems n Technologies for developing systems reviews the evolution of system development to provide an understanding of the underlying principles of building applications n It discusses: ă Underlying technologies ă Development methodologies, and ă Internet-based systems n Case examples include Du Pont Cable Management Services, MGM, Colgate-Palmolive, a telecommunications firm, Hong Kong Exchanges and Clearing and Bekins, with a discussion case on ExxonMobil Today’s Lecture n Introduction n Foundations of Systems Development ă Structured Development ă Fourth-Generation Languages ă Software Prototyping ¨ Computer-Aided Software Engineering (CASE) ¨ Object-Oriented Development ¨ Client-Server Computing Todays Lecture n System Integration ă ERP Systems ă Middleware Introduction Developing new systems = difficult job “if anything can go wrong, it will!” though there is progress in improving the process of buildings systems n ă 1970s: system development life cycle ă 1980s: friendly languages and automation of parts of development such as code generation ă 1990s: n reliance increased on packages Developer productivity & maintenance Introduction cont n Business process reengineering movement = growth on integrated enterprise systems & adoption of enterprise resource planning systems (ERP) n Late 1990s; sudden emergence of e-business and Internet based systems n 2000s - Internet brought need for faster systems development and integrated enterprise systems, ă Hence new tools for rapid development became available – n Relying on reusable components & open systems architecture Introduction cont n n n n These days, virtually every application is a network application, since the network is becoming the system Web-based applications were the first generation of Internet-centric computing The new field, “Web Services” (or whatever people are calling it), is touted as the second In addition, the increasing interconnectedness of supply chains is leading companies to build inter-organizational systems ă Far more complex undertaking than any singlecompany systems Foundations of Systems Development n n n In the early years, systems development was considered a ‘craft’ Then = Discipline through structured development Figure 9-1 is the classic system development life cycle (waterfall approach) ă Much touted but rarely (purely) used ă Developers really always followed the spiral approach as in Figure 9-2 Approaches to integration n n n n n In house: DIY approach to systems and integration Buying external systems from a small number of vendors, thereby either reducing integration issues or passing them on to vendors Ad hoc integration using data dumps and data adaptors Using a central hub between systems sharing data SOA – “This approach, in which resources on a network are made available as independent services that can be accessed without knowledge of the underlying platform implementation, was generally noted as an aspiration or destination rather than a currently existing strategy.” Barriers to further integration n n n n n Lack of resources (costs of staff etc) Lack of in house skills Resistance from academic and service departments wanting to their own thing and protect “their” data Lack of representation of the system integration issue at senior level Lack of understanding in parts of the organization about the multiple uses of data and too much focus on data being used for local purposes only Risks of integration n n n n n n More errors Good integration can make integration invisible, so unappreciated by end users Talk of integration can lead to overambitious user expectations Integration doesn’t always result in more user engagement Vendors can lose enthusiasm leaving organizations with large bills and unfinished work Integration projects can spiral out of scope COLGATE PALMOLIVE Case Example: Successful ERP 1990s = competitive crisis n Used a decentralized structure ¨ Expensive to coordinate ¨ Slow to respond to market changes ă Constraint on company growth n Vision: Become a truly global company, with an integrated business environment and standardized business processes.” n COLGATE PALMOLIVE Case Example: Successful ERP cont n n After setting up a prototype environment in the US, SAP R/3 module convincingly proved itself as being functional and flexible worldwide for ă Sales & distribution ă Materials management ă Finance ă Human resources Savings have been made in IT operations – complex decentralized IT infrastructure was streamlined COLGATE PALMOLIVE Case Example: Successful ERP cont n n n n Implementation took five years and cost $430 million, but it was a success The product delivery cycle dropped and purchasing and other costs were cut Data centers around the world were closed, from 75 down to The complexity of its global data networks was also simplified Success of ERP stems from senior management convincing employees that the company was in crisis and only dramatic change could remedy it Systems Integration Middleware n Most organizations have a wide range of applications ă New and old ă From a variety of vendors ă Running n on numerous platforms Replacing or rewriting these systems not an option Systems Integration Middleware n One option = employ a class of products known as middleware ă Software that works between and connects applications allowing them to share data ă Needed as wide range of applications used and run on numerous platforms ă Simplifies development by acting as the “glue” that binds the components together ¨ There is a wide variety available as illustrated in Figure 9-4 Systems Integration Middleware cont n One type of middleware that has gained popularity: Enterprise Application Integration (EAI): ă Typically use a message broker to transfer data between applications ¨ Add a new level of functionality that distinguishes them Systems Integration Middleware cont ă Allow users to define business processes and make data integration subject to rules that govern those processes n e.g a rule might state that data can only move from purchasing to accounts receivable when ‘X’ has signed off on the purchase A TELECOMMUNICATIONS FIRM Case Example: Enterprise Application Integration n Processing customer requests for new and updated services = major cost and source of customer dissatisfaction ă n It has been estimated that 65 percent of new and change orders in the telephone industry have errors that must be corrected after the fact ($$$) Rather than build a new system, the company looked to EAI to automate the process using three existing systems: A TELECOMMUNICATIONS FIRM Case Example: Enterprise Application Integration The customer relationship management system (which contains the customer information) The ERP system (which retrieves information for the application to validate the request and ensures that the new service is compatible with the customer’s existing services), and The accounting system (which contains the pricing information) A TELECOMMUNICATIONS FIRM Case Example: Enterprise Application Integration cont n n Therefore resolution = ă Customer request service at the call center via the CRM ă Customer’s name and address passed onto ERP system, which retrieve necessary info Mission accomplished ă Decreased processing costs ă Errors eliminated ă Reduced customer churn ă No new applications needed ¨ Existing applications not altered Summary n n Foundations of Systems Development ă Structured Development ă Fourth-Generation Languages ă Software Prototyping ă Computer-Aided Software Engineering (CASE) ă Object-Oriented Development ă Client-Server Computing System Integration ă ERP Systems ă Middleware .. .Technologies for Developing Systems n Technologies for developing systems reviews the evolution of system development to provide an understanding... Engineering (CASE) ă Object-Oriented Development ă Client-Server Computing Todays Lecture n System Integration ¨ ERP Systems ¨ Middleware Introduction Developing new systems = difficult job “if... of e -business and Internet based systems n 2000s - Internet brought need for faster systems development and integrated enterprise systems, ă Hence new tools for rapid development became available