IMS3230 - Information Systems Development Practices

1. IMS3230 - Information Systems Development Practices Blended approaches: Information Engineering

2. Information Engineering • Martin and Finkelstein (1981), Martin (1989), several versions • data oriented methodology • full lifecycle coverage • organisation-wide perspective on planning of information technology and information systems • top-down analysis and development of organisation’s applications • focus on data and activities • well-supported by CASE tools e.g. IEW, IEF • has evolved • widely used

3. Information Engineering evolution • data base technology • data analysis and data management • strategic data models, procedure formation • 4GLs and “productivity tools”, e.g. code generators • alignment of information systems planning with strategic business planning • process modelling techniques • CASE technology, “encyclopedia”, knowledge coordinator • RAD (Rapid Application Development) • object-oriented concepts

4. Information Engineering • data centred: model data requirements first, processes later (data is more stable) applications will be integrated by a common data framework • 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 data processing systems” James Martin (1986) • use of diagrams as a communication and representation tool

5. Major phases of Information Engineering • information strategy planning to build an information and technology architecture to support business strategy and objectives • business area analysis to identify data and function requirements of each business area • individual systems planning • systems design to complete logical specifications for a system and convert these into physical design specifications • construction to generate code, test, and install the system • cutover

6. Phase 1 - information strategy planning: • corporate management and planners assess the organisation: business mission, objectives, CSFs, performance measurements, organisation structure, current situation • construct corporate data model • determine major business functions • identify business areas, including goals and CSFs • determine: information architecture (global entities and business areas) information systems architecture (business sytems) technical architecture (technology: hw/sw/comms) information strategy plan (priorities)

7. Phase 2 - business area analysis: • identify and model in detail the fundamental data and activities required to support a business area • ensure that requirements are independent of technology • ensure that requirements are independent of current systems and procedures • ensure that requirements enable business area’s goals and CSFs to be supported • ensure that requirements are independent of the current organisational structure • a high-level executive sponsor is necessary

8. 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 prioritise system development projects

9. Business area analysis: techniques • data model entity relationship modelling attribute collection normalisation canonical synthesis • process model process decomposition models process dependency diagrams • data and activity interaction entity lifecycles process / entity matrix

10. Information engineering: phases 3 and 4 • Phase 3 - individual systems planning use JRP for individual systems planning • Phase 4 - system design: concerned with how selected processes in the business are implemented in procedures and how these procedures work use the logical data and process models to design the external representations of the system direct end-user involvement is essential identify reusable procedures use prototyping use JAD

11. 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 • on-line procedures and software • batch procedures and software • design verification and testing

12. 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

13. Information Engineering features: • organisation-wide perspective aligned with strategic business planning • comprehensive • emphasis on user involvement e.g. JAD, JRP • evolves by incorporating new techniques, concepts, technologies e.g. RAD, object-oriented concepts • evolves from practice e.g. shortened ISP phase • emphasis on automation e.g. 4GLs, I-CASE, prototypes • primarily for database transaction processing systems • little event or behaviour modelling

14. Information Engineering features: • after ISP phase, activities can proceed in parallel • high level data and process model (co-ordinating model) enables this by highlighting interfaces and dependencies between systems etc. • flexible paths through the methodology e.g. reverse engineering and re-engineering

15. References • Prescribed text: Avison, D.E. & Fitzgerald, G. (2003). Information Systems Development: Methodologies, Techniques and Tools. (3rd ed), McGraw-Hill, London. Chapter 20.3 Refer to additional references in the readings at the unit web page and in the prescribed text