Information Systems Engineering

1. Information Systems Engineering

2. Lecture Outline • Information Systems Architecture • Information System Architecture components • Information Engineering • Phases of Information Engineering • Features of Information Engineering INFORMATION SYSTEM ENGINEERING

3. Information Systems(IS) Planning Introduction : • Sometimes called “enterprise-wide computing” or “Information Architecture” • Scope of (IS Planning) is now the entire organization • There is a problem: isolated groups in an organization start their own databases and it becomes impossible to find out who has what information, where there are overlaps, and to assess the accuracy of the information • To support enterprise-wide computing, there must be enterprise-wide information planning • One framework for thinking about and planning for enterprise-wide computing is an Information Systems Architectureor ISA • Most organizations do NOT have such an architecture INFORMATION SYSTEM ENGINEERING

4. Information Systems Architecture (ISA) • An ISA is a “conceptual blueprint or plan that expresses the desired future structure for information systems in an organization” • It provides a “context within which managers throughout the organization can make consistent decisions concerning their information systems” INFORMATION SYSTEM ENGINEERING

5. Benefits of ISA • Provides a basis for strategic planning of IS • Provides a basis for communicating with top management and a context for budget decisions concerning IS • Provides a unifying concept for the various stakeholders in information systems. • Communicates the overall direction for information technology and a context for decisions in this area • Helps achieve information integration when systems are distributed • Provides a basis for evaluating technology options (for example, downsizing and distributed processing) INFORMATION SYSTEM ENGINEERING

6. Zachman ISA Framework components • Data • The “What” of the information system • Process • The “How” of the information system • Network • The “Where” of the information system • People • Who performs processes and are the source and receiver of data and information. • Events and Points in time • When processes are performed • Reasons • Why: For events and rules that govern processing INFORMATION SYSTEM ENGINEERING

7. Roles of Data, Process and Network • Six perspectives of the Data,ProcessandNetworkcomponents • Business scope (Owner) • Business model (Architect) • Information systems model (Designer) • Technology model (Builder) • Technology definition (Contractor) • Information system (User) INFORMATION SYSTEM ENGINEERING

8. Data Process Network List of locations in which the business operates List of entities important to the business List of processes or functions that the business performs 1. Enterprise Scope (Owner) Explanation of the components INFORMATION SYSTEM ENGINEERING

9. Data Process Network Function and process decomposition Business entities and their relationships Communications links between business locations 2. Enterprise Model (Architect) Explanation of the components (contd….) INFORMATION SYSTEM ENGINEERING

10. Data Process Network Distribution Network Model of the business data and their relationships (ERD in Database design) Flows between application processes 3. Information System Model (Designer) Explanation of the components (contd….) INFORMATION SYSTEM ENGINEERING

11. Data Process Network Database Design (logical) Database Design Process specifications 4. Technology Constrained Model (Builder) Explanation of the components (contd….) INFORMATION SYSTEM ENGINEERING

12. Data Process Network Database Schema and subschema definition Configuration definition/ Network Architecture Program Code and control blocks 5. Technology Definition/ Detailed Representations (Contractor) Explanation of the components (contd….) INFORMATION SYSTEM ENGINEERING

13. Data Process Network Implemented Database and information Implemented Application Programs Current System Configuration 6. Functioning Enterprise (User) Explanation of the components (contd….) INFORMATION SYSTEM ENGINEERING

14. Information Engineering • Information Engineering: “an interlocking set of formal techniques in which enterprise models, data models and process models are built... and are used to create and maintain Information Systems” James Martin (1986) INFORMATION SYSTEM ENGINEERING

15. Information Engineering (contd….) • Object-oriented concepts • Database technology (Relational, Hierarchical, Network ) • Data oriented methodology • Data analysis and data management • Full lifecycle coverage • Focus on data and activities • The use of tools such as CASE(Computer Aided Software Engineering) • Note: CASE tools are a class of software that automate many of the activities involved in various life cyclephases INFORMATION SYSTEM ENGINEERING

16. Information Engineering (contd….) • Strategic data models • Alignment of information systems planning with strategic business planning • Process modeling techniques • top-down analysis and development of organization's applications INFORMATION SYSTEM ENGINEERING

17. Major Phases of Information Engineering 1. Information strategy planning to build an information and technology architecture to support business strategy and objectives 2. Business area analysis to identify data and function requirements of each business area 3. Individual systems planning 4. Individual Systems design to complete logical specifications for a system and convert these into physical design specifications 5. Construction to generate code, test, and install the system 6. Cutover INFORMATION SYSTEM ENGINEERING

18. Phase 1 - information strategy planning: • business mission, objectives, CSFs, performance measurements, organization structure, current situation • construct corporate data model • determine major business area/functions • determine: • information architecture (global entities and business area/functions ) • technical architecture (technology: HW/SW/Comm.) • information strategy plan (priorities) INFORMATION SYSTEM ENGINEERING

19. Phase 2 - Business Area Analysis The Business Area Analysis must help in the following: • identify and model in detail the fundamental data and activities required to support a business area • ensure that requirements enable business area’s goals and CSFs to be supported • ensure that requirements are independent of : • technology • current systems and procedures • current organizational structure • a high-level executive sponsor is necessary INFORMATION SYSTEM ENGINEERING

20. Business area analysis: steps • extract the relevant entity relationship model and business-function decomposition models • identify relevant departments, locations, business goals, CSFs • create a preliminary data model: identify events, entity life cycles, initial attributes • create a preliminary process model: decompose the functions into processes • model data and processes of existing systems for comparison • involve all affected end-users in iteratively building: a detailed data model, a detailed process model, entity / process matrices • identify and priorities system development projects INFORMATION SYSTEM ENGINEERING

21. Business area analysis: techniques • data model entity relationship modeling attribute collection normalization canonical synthesis • process model process decomposition models process dependency diagrams • data and activity interaction entity lifecycles process / entity matrix INFORMATION SYSTEM ENGINEERING

22. Information engineering: phases 3 and 4 • Phase 3 - individual systems planning Although it is individual but we have to use JRP (Joint Requirement Planning) for individual systems planning • Phase 4 - individual system design • concerned with how selected processes in the business are implemented in procedures and how these procedures work • direct end-user involvement is essential • identify reusable procedures • use prototyping • use JAD (Joint Application Design) INFORMATION SYSTEM ENGINEERING

23. System design techniques • prototyping • detailed process models: procedure design using access path and volumes analysis, dialogue flows and menu structures, • physical database design, file design, • screen displays • menu flows • report layouts • batch procedures and software • design verification and testing INFORMATION SYSTEM ENGINEERING

24. Information engineering: phases 5 and 6 • Phase 5 - construction: technical design, create physical databases create modules and programs, unit testing system testing, documentation • Phase 6 - cutover: conversion final testing conduct training install the system, review implementation INFORMATION SYSTEM ENGINEERING

25. Information Engineering Features • organization-wide perspective aligned with strategic business planning • Comprehensive (complete, full) • emphasis on user involvement e.g. JAD, JRP • evolves by incorporating new techniques, concepts, technologies e.g. object-oriented concepts • emphasis on automation e.g. 4GLs, I-CASE, prototypes INFORMATION SYSTEM ENGINEERING

26. Information Engineering Features (Contd….) • primarily for database transaction processing systems • flexible paths through the methodology e.g. reverse engineering and re-engineering INFORMATION SYSTEM ENGINEERING

27. References • Avison, D.E. & Fitzgerald, G. (2003). Information Systems Development: Methodologies, Techniques and Tools. (3rd ed), McGraw-Hill, London. Chapters 20.1, 20.3 • www.courses.ischool.berkeley.edu • www.slideserve.com/.../information-systems-planning- • www.ou.edu/class/aschwarz/Database/ INFORMATION SYSTEM ENGINEERING