1. CIS 321—IS Analysis & Design
Chapter 2: Approaches to System Development

2. Overview Systems development can be very complex.
The systems development ______ cycle (SDLC) framework can help address this complexity.
Other aids in systems development are
methodologies
models
tools
_________
Two major approaches to systems development:
traditional
object-oriented

3. The Basic SDLC Project definition: System development project
A planned endeavor with a beginning and an end that produces a desired result
System development project
The result is an information system
A complex project requires a detailed plan
Five phases of system development
project planning—initiate, plan, obtain approval
analysis—determine requirements
design—define the solution
implementation—implement the solution
support—maintain and enhance the system

4. Project Planning Phase
Define the problem
existing system
proposed system
Produce the project _________
establish milestones
Confirm project _________
economic, organizational, technical, resource, schedule
Staff the project
select/acquire the staff and allocate time
Launch the project
management approval, allocation of resources

5. Analysis Phase Gather information Define system requirements
learn about the problem _________, users, stakeholders
Define system requirements
draw diagrams
Build ___________ of system components
to discover additional requirements
Prioritize requirements
Generate and evaluate alternatives
develop in-______, buy a package, contract w/ third party
Review recommendations with management
choose alternative, proceed

6. Design Phase Design and integrate the network
hardware, operating systems
Design the application architecture
addresses problem domain requirements
Design the user __________
forms, reports, screens, etc.
Design the system interfaces
communicating with other systems
Design and integrate the database
Prototype for design details
prototypes can be saved for the final system
Design and integrate the system controls (security)

7. Implementation Phase Construct software components Verify and test
using VB .NET, Java, etc.
Verify and test
all possible situations
Convert data
populate the database
Train users and document the system
avoid frustrated users
Install the system
prototype, parallel systems, complete changeover

8. Support Phase Debug the system Upgrade the system Enhance the system
corrective maintenance
Upgrade the system
_________ maintenance
Enhance the system
Support the users
help desk

9. SDLC & the Element of Time
Waterfall approach
each phase is completed before the next one begins
Overlapping of phases
speed development, required by the nature of the problem
_________ of phases
perform the same phase repeatedly until it’s good enough to begin the next phase
each iteration of one phase provides new information about the previous phase
Divide project into miniprojects (UI, apps, DB)
____________ development
deliver part of the system before the whole system

10. Aids for Completing the SDLC
Methodologies
a collection of techniques for how to use tools to create models
Models
A model is an ___________ of something in the real world
Models can be physical, mathematical, graphical, textual
Flowchart, DFD, ERD, structure chart, use case diagram, …
Project planning models (PERT and Gantt charts)
Tools
software support to create models or even program code
Techniques
step-by-step instructions

11. Traditional Approach to System Development
Structured programming
Three structures: sequence, selection, __________
top-down programming (modular programming)
Structured design
modules arranged in a structure chart
modules are loosely coupled and highly __________
Structured analysis
data flow diagram (DFD)
entity-relationship diagram (ERD)
Information engineering (James Martin)
rigid focus on strategic planning, data, CASE

12. Object-oriented System Development (OOSD)
A thing that encapsulates attributes and behavior
OO analysis
identifying problem domain objects and their relationships
OO design
identifying system objects (people, devices)
OO programming
C++, Java, C#
A class is a specification of one type of object
OOSD is more natural, leads to reuse (?)

13. SDLC Variations Variations of names for phases
planning, feasibility study, investigation, strategy planning
construction, transition, implementation
Variations based on _______-computer interaction
sociotechnical systems
Multiview
soft systems methodology
Variations based on speed of development
_______ application development (RAD)
prototyping

14. Current Trends in Development 1
Spiral model
highly iterative
create series of prototypes
begin with areas of greatest risk
eXtreme Programming (XP)
developed by Kent Beck
user ________
series of releases
two programmers work together
work only ____ hours per week

15. Current Trends in Development 2
Unified Process (UP)
developed by Booch, Rumbaugh, Jacobson of _________ Software
designed for OOSD
uses UML (________ Modeling Language)
phases: inception, elaboration, construction, transition
Agile Modeling
developed by Scott Ambler
mix between the lightweight XP and the heavy duty UP
iterative and incremental
teamwork
simplicity
validation