VCE IT Theory Slideshows
Problem Solving Methodology 2
DESIGN
By Mark Kelly
McKinnon Secondary College
Vceit.com
Contents
• What needs designing?
• Design tools
Design...
• How the solution will work
• What interfaces and output will look like
Need to design
•
•
•
•
Hardware needs
Software needs
Training and documentation requirements
Procedures that need to be created or
changed
• Evaluation criteria
Tools
•
•
•
•
•
data dictionaries and data structure diagrams,
input-process-output (IPO) charts,
flowcharts,
pseudocode,
object descriptions.
Designing how bits of the solution
fit together – e.g.
• Website pages, style sheets, scripts;
• Database queries, forms, reports;
• Program modules, procedures, functions.
Useful tools for this
• Website: storyboards, site maps
• Database: entity-relationship diagrams, data
flow diagrams, structure charts,
• Multipurpose: hierarchy charts, context
diagrams, use cases.
Design
• Consider alternative designs
• More than one way to skin a cat
• Some designs may be technically great,
but unacceptable because of constraints
Design
• Every solution has both pros and cons
• What’s acceptable to a developer might
be impossible for the client
• Selecting a design strategy means
achieving maximum “pros” with
minimum “cons”
• What is a pro or con varies from client to
client
Physical Design Tools
• These actually plan how to build a
system
• They give instructions on what to do
– Physical data dictionaries (e.g.
“Customer_Surname is string, 25
characters”)
– Data Flow Diagrams...
Physical Design Tools
–Storyboards
–Flow Charts, Nassi-Shneiderman charts
–Structure Charts
–IPO charts
–Layout diagrams / mockups
–Pseudocode
Designing appearances
• layout diagrams,
• annotated diagrams/mock ups
• prototypes
Designing the evaluation criteria
• What measures will be used to judge whether
or not the solution requirements have been
met?
• Should relate to the solution requirements
identified in the analysis stage’s logical design.
Design
• Must be documented
• If successful, will lead to Development
phase. If not, cancel the project.
• Is used as a strict instruction manual
during the following phases, particularly
during Development
VCE IT THEORY SLIDESHOWS
By Mark Kelly
McKinnon Secondary College
vceit.com
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