1. Approaches to Systems Development
Chapter 8

2. Outline Introduction Ch 8 - Approaches to System Development
Systems Analyst
Ch 8 - Approaches to System Development
SDLC
Phases & Core Processes
Approaches: Predictive & Adaptive
Methodology
Software Construction & Modeling Approaches
Structured A&D
Object-oriented
Agile Development

3. Systems Analyst
Organizational role most responsible for analysis and design of information systems.
Translates a _________ __________ into an ___________ ___________ ___________ .
Job Titles
vary by organization; read the job description
Systems Analyst
Business Analyst (client-facing)

4. …more of a business problem solver than a technical programmer
Systems Analyst
…more of a business problem solver than a technical programmer
Knowledge & Skills
Technical
DB, Programming, Computers Hardware, Networking, Operating systems, and utilities, Communication & collaboration technology
SDLC techniques
Business
Organizational knowledge
Management techniques
Functional work processes
People
Communication skills
Interpersonal Skills
Roles: Negotiator, Teacher, Mentor, Collaborator, Manager

5. Systems Development Project
Is a planned undertaking
Has fixed beginning and end
Produces desired result or product
Varies in size

6. SDLC: Systems Development Life Cycle
Provides overall framework for managing systems development process
All projects use some variation of SDLC
Phase
Project Initiation
Planning
Analysis
Design
Implementation
Deployment
Core Process
1. Identify the problem/need & obtain approval
2. Plan & monitor the project
3. Discover & understand the details
4. Design the system components
5. Build, test, and integrate system components
6. Complete system tests and deploy solution
Ch 9
Ch 9
Ch 2-5
Ch 7,10-12
Ch 13
Ch 13

7. 2 Approaches to the SDLC Assumptions Assumptions Predictive SDLC
Adaptive SDLC
Waterfall Model
Modified Waterfall
Spiral Model
Incremental Development
Assumptions
can be planned in advance
system can be developed according to the plan
Assumptions
Iterative
Must be flexible & adapt

8. Predictive Approaches
Waterfall
One phase begins when another completes; Specifications are frozen
Support
Deployment
Planning
Analysis
Design
Implementation
Project Initiation
Problems
System requirements “locked in”
Limited user involvement
Too much focus on milestone deadlines
Modified Waterfall
Overlapping phases
Can go backwards
Support
Deployment
Planning
Analysis
Design
Implementation
Project Initiation

9. Adaptive Approaches: Spiral Model
An iterative approach
Spiral until project completion
Then, deployed!
Project Management:
managed differently than a waterfall approach

10. Adaptive Approaches: Incremental Development
Also, an iterative approach
BUT…
System is built in small increments; it is "grown"
As an iteration is completed it is integrated to the whole
Partially deployed in steps
Advantage
some functionality gets into the user's hands much earlier

11. Methodology
A comprehensive guideline to follow for completing every SDLC activity
Abstraction used
to separate out
aspect
Methodology
Models
Techniques
Tools
Software to
create models
or other project
components
Guidelines
or instructions

12. 2 Approaches to Software Construction & Modeling
Structured Approach
analysis, design & programming
Object-oriented Approach

13. Software Construction & Modeling: Structured Approach
Analysis
Structured
Design
Structured
Programming
Define processing requirements
Define data requirements
Define inputs and outputs
Define how functions work together to accomplish tasks
Determines set of programs
Purpose of each
Organization of programs
Main principles:
Loosely coupled
Highly cohesive
Each program has one beginning & one ending
Uses 3 constructs:
Sequence
Decision
Repetition
Improvements:
program quality
easier to maintain

14. Software Construction & Modeling: Object-Oriented Approach
Views information system as a collection of interacting objects that work together to accomplish tasks
OOA, OOD, OOP
OO languages
C++, Java, C#
Benefits
Reuse!

15. Agile Development A guiding philosophy and set of guidelines for :
developing information systems in an unknown rapidly changing environment
Complements Adaptive SDLCs & Methodologies
makes sure developers are fast to respond to changes
“Manifesto for Agile Development”  agilemanifesto.org
Value responding to change over following a plan
Value individuals and interactions over processes and tools
Value working software over comprehensive documentation
Value customer collaboration over contract negotiation