IMS5006 - Information Systems Development Practices

1. IMS5006 - Information Systems Development Practices Quality and productivity issues in information systems development: CASE tools and prototyping

2. Quality and productivity “solutions” include: • user participation • JAD (Joint Application Design) • prototyping • automated and other tools • RAD (Rapid Application Development) • reuse

3. Quality and productivity • in what ways have system development methodologies been influenced by these initiatives? • how have techniques and tools relating to these initiatives been incorporated into system development methodologies?

4. Prototyping • Prototype • a working model of some aspect(s) of an information system • Prototyping • an iterative process of quickly building an experimental system, for demonstration and evaluation so that users can dynamically determine their information requirements and explore and test the design of the system

5. Prototyping • Can be used in various phases of the SDLC • Initiation - to test the feasibility of a particular technology that might be applied for an IS • Analysis - to discover users’ requirements by ‘painting’ screens and reports to solicit feedback • Design - to simulate the ‘look and feel’ of the system and evaluate how easy it is to use and learn • Implementation - prototype evolves directly into the production system, to train users

6. Prototyping • A prototype is designed with an expectation of change - expect to get it wrong the first time! • Need appropriate technology • Types of prototypes • features eg external design mock-up • throw-away • evolutionary

7. Prototyping • Useful • when there is uncertainty about requirements or design solutions • can capture requirements in concrete, rather than verbal or abstract form • users are more likely to be able to state their detailed requirements when they see and use a prototype • users are more likely to get what they want

8. Prototyping • Useful • when there are several stakeholders • convenient display method for multiple parties • because it encourages user participation • user can relay feedback immediately • changes can be made interactively • because it is easier to identify behavioural issues when users are using the prototype • the designer can interactively accommodate the way the user ‘uses’ the interface

9. Prototyping Prototyping in information systems development: • can assist with defining system requirements • can improve the system design process • a communication tool, a learning vehicle • increases development speed (maybe) • widely accepted technique a prototype is designed with an expectation of change

10. Prototyping • Limitations • tends to skip through analysis and design phases too quickly --> lack of thorough understanding of the problems • a tendency to avoid creating formal documentation of system requirements which can then make the system more difficult to develop into a production system • can discourage consideration of a wide range on alternative design options .. tendency to go with the first one that the user likes

11. Prototyping • Limitations • often lacks flexibility, technical efficiency and maintainability because of hasty construction • not suitable for large applications which have large amounts of data and multiple users - hard to control • often built as stand-alone systems, thus ignoring issues of data sharing and interactions with other existing systems

12. Prototyping • Limitations • checks in the SDLC are bypassed so tendency to gloss over essential tasks eg. feasibility, standardisation, documentation, testing, security, etc.. • can become too specific to the user representative and difficult to adapt to other potential users

13. Prototyping Roles of prototypes • Functional prototypes: demonstrate, test and evaluate functionality • Process prototypes: processes, sequences, responses etc. • Design prototypes: external design features • Performance prototypes: response times, loads, volumes, etc.

14. Prototyping • prototyping as a technique: can be incorporated into a systems development methodology (analysis, design, construction) • prototyping as basis for a system development methodology: uses an iterative lifecycle model e.g. requirements analysis build prototype evaluate prototype refine prototype construct system using prototype as part of the specification

15. Prototyping Potential advantages of prototyping: • users see something concrete early on • improved understanding and learning/discovery • make changes quickly and easily Potential disadvantages of prototyping: • poorly documented systems • incomplete systems • unrealistic user expectations • project management difficulties

16. Prototyping and ISD methodologies for information systems development methodologies (ISDMs): • changed view of the lifecycle • less emphasis on paper-based documentation • widespread acceptance: ISDMs need to keep up-to-date with latest trends in technology has prototyping improved system development?

17. Prototyping and evolutionary development • Evolutionary development (vs traditional, linear SDLC) incremental approach delivering a system in stages: the system evolves (is built) over time • Each delivery achieves something usable, useful but not necessarily complete: a series of development efforts (see Fig 6.1 Avison & Fitzgerald 2003, p. 86) • Approach: • Design does not have to be perfect, but something is delivered • Accommodate future change • Does not have to be comprehensive • Appropriate for situations with unclear requirements: system is developed as more is learned about the problem situation • Evolutionary prototyping uses an evolutionary development approach where the prototype evolves into the final system

18. What are CASE tools? • computer-aided software tools that provide automated support for some portion of the systems development process • provide an engineering-type discipline to improve productivity and increase the quality of information systems • CASE tools may run on various mini and mainframe systems, but the PC is the dominant CASE workstation

19. CASE tools • CASE (Computer Assisted Software Engineering) tools Objective of CASE tool usage: • higher quality systems, a less expensive and more productive system development process “automated and integrated software development tools, techniques and methodologies that add significant value by increasing the productivity of the application development process and the quality of the applications that they're used to develop” Stone (1993) p.8

20. CASE tools Objectives • to improve the quality of the systems developed: e.g. better and more complete specifications and designs • to improve the productivity of systems development: less people and faster • to ease and improve consistency of specifications, conformity of designs, and testing through automated checking • to improve the integration of development activities via the use of common methodologies and techniques • to improve the quality and completeness of documentation

21. CASE tools Objectives • to improve the management and control of projects • to promote consistency across projects within the organisation • to promote consistency and quality of systems across the organisation • to promote resuability • to reduce maintenance effort

22. CASE tools core CASE tool functionality: • graphical facilities for diagrams and modelling • data dictionary • automated documentation additional functionality: • code generation from system specifications and models • automatic audit trail of changes • project management facilities • enforced diagramming and documentation standards

23. Components of CASE Tools • diagramming tools • screen and report generators • analysis tools • a central repository • documentation generators • code generators

24. Components of CASE Tools • diagramming tools enable graphical representation of system data, processes, and control structures • screen and report generators help to prototype how systems “look” and “feel” to users help to identify data and process requirements • analysis tools automatic checking for correctness, completeness, and consistency of specifications in diagrams, reports, forms

25. Components of CASE Tools • a central repository enables integrated storage of systems specifications and project management information • documentation generators help to produce both technical and user documentation in standard formats • code generators automatic generation of program and database definition code directly from the design documents, diagrams, reports and forms

26. CASE tools: the CASE repository • the repository is central to the CASE tool for integration to allow sharing between tools and SDLC activities • a centralised database containing all form and report definitions, diagrams, data definitions (data flows, entities etc), process flows, functions, process logic, other organisational and system components • common terminology, notations, methods to support integration • potential benefits: supports co-ordination of team members and effort promotes reusability

27. Types of CASE tools • Upper CASE designed to support the earlier lifecycle phases: IS planning, project identification and planning, systems analysis, design • Lower CASE designed to support the implementation and maintenance phases of systems development • I-CASE (integrated CASE) “seamless” integration of products and tools across lifecycle phases via a common repository (see Avison & Fitzgerald 2003, Chapter 18)

28. CASE tool usage • Cross lifecycle CASE CASE tools used to support activities that occur across multiple phases of the SDLC e.g. • project management: developing estimates of time and resources, scheduling, monitoring project progress • production of documentation the repository and document generators are used across multiple lifecycle phases

29. Implementing CASE tools in organisations • the adoption of CASE is closely related to the use of a formal, standardized systems development process or methodology: many CASE tools force or encourage analysts to follow a specific methodology organizations without a widely used methodology or an approach that is compatible with a CASE tool will have difficulties • CASE adoption has been slower than expected due to several factors including: cost, training needs, front end lifecycle effort

30. Implementing CASE tools in organisations • startupcosts I-CASE costs per analyst: $5,000 to $50,000 only large-scale system builders can spend this smaller organisations use tools with less functionality • training for every dollar spent on tools, half to double that spent on training • front end lifecycle effort the big benefits come in later lifecycle phases: construction, testing, implementation, maintenance early phases lengthened by up to 40% (see Hoffer et al 2002, chapter 4)

31. Why organisations resist CASE tools • common resisting organisational factors for CASE adoption: • high cost of purchasing • high cost of training personnel • low organisational confidence in the IT department to deliver high quality systems on time and within budget • lack of methodology and standards • CASE seen as a threat to job security • lack of confidence in CASE products

32. CASE tool implementation critical success factors: • the right tools • a CASE implementation strategy • a systems development methodology • the methodology must be structured to facilitate the use of CASE tools • a CASE-compatible culture • appropriate human resources • appropriate expectations

33. Selecting CASE tools • compatible with systems development methodology/approach • compatible with technology architecture • development and application environment • organisational culture • implementation strategy • vendor support

34. Systems development using CASE tools • changes in work practices: • focus on analysis and design • “automatic” documentation generation • maintain designs • modifications to analysis and design products • project management • project team structures • task structures • differences between CASE-based vs manual versions of SDMs

35. Evolution and future of automated tools • Visual development tools: • rapidly build interfaces, reports etc using visual tools e.g. Visual Basic, Powerbuilder and instantly test the look of the design (development and programming environments) • Embed AI into development environments • use of intelligent agents (programs) residing in a computer to carry out developer’s instructions to create new systems

36. References • Prescribed text: Avison, D.E. & Fitzgerald, G. (2003). Information Systems Development: Methodologies, Techniques and Tools. (3rd ed), McGraw-Hill, London. Chapters 9.2, 18, 6.1, 6.2, 6.3 • HOFFER, J.A., GEORGE, J.F. and VALACICH (2002) 3rd ed., Modern Systems Analysis and Design, Prentice-Hall, New Jersey, Chapter 4