INFS 6225 Object-Oriented
Systems Analysis & Design
Chapter 11: Physical Architecture
Layer Design
Architecture Design
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Plan for Hardware, Software, & Infrastructure
Part of the System Architecture Layer
Designed based on business needs specified in the
Analysis Phase
Three Main Designs
1.
Server-Based – all functions performed on server
(e.g., Mainframe configuration)
2.
Client-Based – data stored on server, all other
functions performed on local PC
3.
Client-Server – data & data access on server,
application & presentation performed on local PC
1.
2.
Fat Client – more application logic on local PC
Thin Client – less application logic on local PC
Tiered Architecture
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All Client PCs count as
one tier
Each Server PC counts
as one tier
Four-tier client-server architecture >>
Network Models
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Shows major components (e.g., servers,
communication lines, networks) & their
geographic location
Show complexity of system
Show how components fit together
No standards for creating Network Models
Nonfunctional Requirements

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Operational – specifies operating environment
Performance – response time, capacity, &
reliability
Security – protection from disruption & data
loss
Cultural & Political –specific requirements of
host countries
Nonfunctional Requirements
Continued

Operational
Technical – HW, SW, & NW specifications
 System Integration – interface w/ other systems
 Portability – operation in other environments
 Maintainability – adapting to changing business
requirements

Nonfunctional Requirements
Continued

Performance
Speed – response time
 Capacity – volume of data & users (total & peak)
 Reliability – operational vs. not operational

Nonfunctional Requirements
Continued

Security
System Value – estimated value of system & data
 Access Control – who can access what
 Encryption/Authentication – protection of data
across networks/Internet
 Virus Control – control spread of viruses

Nonfunctional Requirements
Continued

Cultural & Political
Multilingual – language(s) of host country
 Customization – user-defined fields & formats
 Unstated Norms – use of local date, currency,
measurement formats & labels
 Legal – abiding by host country(s) laws
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System Specification
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Document that describes the HW & SW
needed to support the system
Three main steps to create:
1.
2.
3.
List all HW needed
Describe minimum requirements for each piece of
HW
List SW to run on each piece of HW