1. ZEIT2301- Design of Information Systems
ZEIT2301 Design of IS
Week 01: Intro
ZEIT2301- Design of Information Systems
School of Engineering and Information Technology
Dr Kathryn Merrick
Session 2, 2010

2. ZEIT2301 Design of IS
Week 01: Intro
Week 01: Intro
Topics:
Review of the systems development lifecycle (SDLC) and its phases
Introduction to the database development lifecycle (DBLC) and phases
References:
Dennis, A., Wixom, B.and Tegarden, D., Systems Analysis and Design with UML Version 2.0: An Object-Oriented Approach, 3rd edition, 2009, John Wiley. (Chapter 1)
Connolly, T., Begg, C., Database Solutions: A step-by-step guide to building databases, Second Edition, Pearson, (Chapter 4)
Session 2, 2010

3. Systems Development Lifecycle
ZEIT2301 Design of IS
Week 01: Intro
Systems Development Lifecycle
The SDLC consists of phases/activities traditionally used to conceive, develop and maintain information systems.
Different variants of the lifecycle exist.
The textbook identifies four phases
Planning, Analysis, Design, Implementation
Session 2, 2010

4. SDLC Phases 1. Planning (actually initiation, then planning)
ZEIT2301 Design of IS
Week 01: Intro
SDLC Phases
1. Planning (actually initiation, then planning)
Why build the system?
2. Analysis
Who, what, when, where of the system?
3. Design
How will the system work?
4. Implementation
System delivery
Session 2, 2010

5. 1. Planning Identifying business value Evaluate feasibility
ZEIT2301 Design of IS
Week 01: Intro
1. Planning
Identifying business value
Does the project align with key business objectives?
Evaluate feasibility
Technical, economic, organizational
Develop work plan
Staff the project
Control and direct project
Session 2, 2010

6. 2. Analysis Requirements Gathering/Elicitation Requirements Modelling
ZEIT2301 Design of IS
Week 01: Intro
2. Analysis
Requirements Gathering/Elicitation
Gather the requirements (using various techniques, e.g. interviews, document analysis, etc)
Requirements Modelling
Develop a set of analysis models that represent both the data and processes necessary to support the business
Requirements Specification
Document the requirements in a system/software requirements specification document
Session 2, 2010

7. 3. Design Develop a design strategy Hardware, software, networks
ZEIT2301 Design of IS
Week 01: Intro
3. Design
Develop a design strategy
Design architecture and interfaces
Hardware, software, networks
Interface design
Forms, reports, web pages
Database and file design
Program design
Session 2, 2010

8. 4. Implementation Construction System is built (or acquired)
ZEIT2301 Design of IS
Week 01: Intro
4. Implementation
Construction
System is built (or acquired)
System testing
Installation
Implement a training plan for the users
New system becomes operational
Operation & Maintenance
Establish a support plan
Session 2, 2010

9. Processes and Deliverables
ZEIT2301 Design of IS
Week 01: Intro
Processes and Deliverables
Process
Product
Planning
Analysis
Design
Implementation
Project Proposal and Plan
Requirements
Specification
Code
User Manual
Session 2, 2010

10. Database Development Lifecycle
Planning
Analysis
Design
DBMS Selection
Implementation
Maintenance

11. 1. Planning
Management activities that permit the stages of the database system development lifecycle to be realised efficiently and effectively
Creation of a mission statement and objectives
Development of standards for data collection and format

12. 2. Analysis
Collecting and analysing information about the organisation to be supported by the new database system
Using this information to identify the requirements of the new database
A preliminary part of database design

13. 3. Database Design
Creating a design that will support the organisation’s mission statement and objectives
Other design processes:
Application design
Transaction design
User interface design

14. Database Management Software
Shared collection
of logically
related data
Applications
Interact with
database via
DBMS
Database Management
Software (DBMS)
Methods to define, retrieve
update and maintain data

15. 4. DBMS Selection

16. 5. Implementation
Physical realisation of the database and related applications
Includes data conversion and loading
Testing

17. 6. Maintenance
Monitoring and maintaining the database system following installation

18. Systems development: Some terminology
ZEIT2301 Design of IS
Week 01: Intro
Systems development: Some terminology
Methodology: A comprehensive approach to system development; typically includes activities, techniques, and tools
Technique: a collection of guidelines that help an analyst complete an activity or task
Tool: a specific device, usually software, which makes it easier to use a specific technique
Session 2, 2010

19. System Development Methodologies
ZEIT2301 Design of IS
Week 01: Intro
System Development Methodologies
Historically methodologies tended to be either process-centred or data-centred.
More recently the object-oriented approach seeks to integrate both process and data in a single model.
Large organizations may follow internal methodologies or formal standards.
For a complex information system, a systematic approach is crucial.
Well-known methodologies include:
Waterfall development
Parallel development
Rapid application development
Agile development
Session 2, 2010

20. Categories of Methodologies
ZEIT2301 Design of IS
Week 01: Intro
Categories of Methodologies
Structured Design
Waterfall Development
Parallel Development
Rapid Application Development
Phased
Prototyping
Throwaway Prototyping
Agile Development
eXtreme Programming
Session 2, 2010

21. ZEIT2301 Design of IS
Week 01: Intro
“Structured” Design
The advent of “Structured” design introduced formal models:
Typically used one set of models to describe process (eg Data Flow Diagrams) and a separate set of models to describe data (eg Entity-relationship Diagrams)
Structured development methodology involved a formal step-by-step approach
Most well known methodology is the Waterfall method
Moves from one phase to the next in sequence
Many variants; later variants allowed for iteration where necessary
Session 2, 2010

22. Structured Design 1 Waterfall Development ZEIT2301 Design of IS
Week 01: Intro
Structured Design 1
Waterfall Development
Session 2, 2010

23. Pros and Cons of the Waterfall Method
ZEIT2301 Design of IS
Week 01: Intro
Pros and Cons of the Waterfall Method
Pros
Cons
Identifies systems
requirements long
before programming
begins
Requirements must
be fully specified
before programming
begins
Long delay before
delivery of product;
Highly formalized;
Inflexible;
Session 2, 2010

24. Structured Design 2 Parallel Development: sub-projects
ZEIT2301 Design of IS
Week 01: Intro
Structured Design 2
Parallel Development: sub-projects
developed separately
Session 2, 2010

25. Pros and Cons of Parallel development
ZEIT2301 Design of IS
Week 01: Intro
Pros and Cons of Parallel development
Pros
Cons
Divides project into sub-projects that can be worked on in parallel thus allowing
earlier delivery of the system
Subsystems might not be independent; could require significant integration effort
Session 2, 2010

26. Rapid Application Development
ZEIT2301 Design of IS
Week 01: Intro
Rapid Application Development
Rapid Application Development (RAD)
Concentrates on developing at least part of the system much earlier
Involving users for feedback
Use of tools to speed development
Session 2, 2010

27. Rapid Application Development
ZEIT2301 Design of IS
Week 01: Intro
Rapid Application Development
Key features
CASE tools (Computer-Aided Software Engineering)
JAD sessions (Joint Application Development)
Fourth generation/visualization programming languages
Code generators
Eg generate code from models/diagrams
Session 2, 2010

28. RAD based approaches Phased Development Prototyping
ZEIT2301 Design of IS
Week 01: Intro
RAD based approaches
Phased Development
A series of versions; initial version meets key requirements
Prototyping
System prototyping
Prototype evolves to become the system
Throw-Away Prototyping
Design prototyping
Prototype is used only to help determine requirements
Session 2, 2010

29. Rapid Application Development 1
ZEIT2301 Design of IS
Week 01: Intro
Rapid Application Development 1
Phased Development
Version1, version 2, etc
Session 2, 2010

30. Rapid Application Development 2
ZEIT2301 Design of IS
Week 01: Intro
Rapid Application Development 2
System Prototyping
The prototype evolves to become the actual system
Session 2, 2010

31. Rapid Application Development 3
ZEIT2301 Design of IS
Week 01: Intro
Rapid Application Development 3
Throwaway Prototyping
The prototype is only used to help elicit requirements and thus inform system design.
Session 2, 2010

32. Agile Development Agile development Extreme Programming
ZEIT2301 Design of IS
Week 01: Intro
Agile Development
Agile development
Drastically reduces the modelling and associated documentation phases
Concentrates on programming (ie producing working code)
Extreme Programming
Develop code rapidly and involve users
Pair programming using skilled programmers
Rapid incremental development; continuous release of product to users
Session 2, 2010

33. Agile Development Extreme Programming ZEIT2301 Design of IS
Week 01: Intro
Agile Development
Extreme Programming
Session 2, 2010

34. Criteria for Selecting the Appropriate Methodology
ZEIT2301 Design of IS
Week 01: Intro
Criteria for Selecting the Appropriate Methodology
Clarity of user requirements
Familiarity with technology
System complexity
System reliability
Short time schedules
Schedule visibility
Session 2, 2010

35. Criteria for selecting a Methodology
ZEIT2301 Design of IS
Week 01: Intro
Criteria for selecting a Methodology
Criteria
Waterfall
Parallel
Phased
Prototyping
Throwaway Prototyping
Extreme Programming
Unclear user requirements
Poor
Good
Excellent
Unfamiliar technology
Complex systems
Reliable systems
Short time schedule
Schedule visibility
Session 2, 2010

36. Object-Oriented Analysis & Design
ZEIT2301 Design of IS
Week 01: Intro
Object-Oriented Analysis & Design
Attempt to balance emphasis on data and process
Uses Unified Modelling Language (UML)
Characteristics of OOAD:
Use-case Driven
Architecture Centric
Iterative and Incremental
Session 2, 2010

37. Skills of the systems analyst
ZEIT2301 Design of IS
Week 01: Intro
Skills of the systems analyst
Analytical
systems thinking, organisational knowledge, problem identification, problem analyzing and solving
Technical
Computers, networks, databases, operating systems, Internet, programming languages
Management
Resource management, project management, risk management, change management
Interpersonal
Communications skills, ability to work in a team, group facilitation, managing expectations
Session 2, 2010

38. The Analyst’s Approach to Problem Solving
ZEIT2301 Design of IS
Week 01: Intro
The Analyst’s Approach to Problem Solving
Session 2, 2010

39. Project Team Roles Role Responsibilities Business Analyst
ZEIT2301 Design of IS
Week 01: Intro
Project Team Roles
Role
Responsibilities
Business Analyst
Analyzing the key business aspects of the system
Identifying how the system will provide business value
Designing the new business processes and policies
Systems Analyst
Identifying how technology can improve business processes
Designing the new business processes
Designing the information system
Ensuring the system conforms to IS standards
Infrastructure Analyst
Ensuring the system conforms to infrastructure standards
Identifying infrastructure changes required by the system
Change Management Analyst
Developing and executing a change management plan
Developing and executing a user training plan
Project Manager
Managing the team
Developing and monitoring the project plan
Assigning resources
Serving as the primary point of contact for the project
Session 2, 2010

40. ZEIT2301 Design of IS
Week 01: Intro
Summary
The SDLC consists of four stages: Planning, Analysis, Design, and Implementation
The DBLC consists of six stages: Planning, Analysis, Design, DBMS Selection, Implementation, Maintenance
System development methodologies vary
The choice of an appropriate methodology depends on the characteristics of the system, the organisation and the available staff skill set.
Session 2, 2010