INFS 6225 Object-INFS 6225 Object-Oriented Systems Oriented Systems Analysis & DesignAnalysis & Design

Chapter 11: Physical Chapter 11: Physical Architecture Layer DesignArchitecture Layer Design

Architecture DesignArchitecture Design

Plan for Hardware, Software, & Plan for Hardware, Software, & InfrastructureInfrastructure

Part of the System Architecture Part of the System Architecture LayerLayer

Designed based on Designed based on business needsbusiness needs specified in the Analysis Phasespecified in the Analysis Phase

Three Main DesignsThree Main Designs

1.1. Server-BasedServer-Based – all functions performed on – all functions performed on server (e.g., Mainframe configuration)server (e.g., Mainframe configuration)

2.2. Client-BasedClient-Based – data stored on server, all – data stored on server, all other functions performed on local PCother functions performed on local PC

3.3. Client-ServerClient-Server – data & data access on – data & data access on server, application & presentation server, application & presentation performed on local PCperformed on local PC

1.1. Fat Client – more application logic on local PCFat Client – more application logic on local PC2.2. Thin Client – less application logic on local PCThin Client – less application logic on local PC

Tiered ArchitectureTiered Architecture

AllAll Client PCs Client PCs count as one tiercount as one tier

EachEach Server PC Server PC counts as one tiercounts as one tier

Four-tier client-server architecture >>

Network ModelsNetwork Models

Shows major components (e.g., Shows major components (e.g., servers, communication lines, servers, communication lines, networks) & their geographic networks) & their geographic locationlocation

Show complexity of systemShow complexity of system Show how components fit togetherShow how components fit together NoNo standards for creating Network standards for creating Network

ModelsModels

Nonfunctional Nonfunctional RequirementsRequirements

Operational – specifies operating Operational – specifies operating environmentenvironment

Performance – response time, Performance – response time, capacity, & reliabilitycapacity, & reliability

Security – protection from disruption Security – protection from disruption & data loss& data loss

Cultural & Political –specific Cultural & Political –specific requirements of host countriesrequirements of host countries

Nonfunctional Nonfunctional RequirementsRequirements

Continued Continued Operational Operational

Technical – HW, SW, & NW Technical – HW, SW, & NW specificationsspecifications

System Integration – interface w/ other System Integration – interface w/ other systemssystems

Portability – operation in other Portability – operation in other environmentsenvironments

Maintainability – adapting to changing Maintainability – adapting to changing business requirementsbusiness requirements

Nonfunctional Nonfunctional RequirementsRequirements

Continued Continued Performance Performance

Speed – response timeSpeed – response time Capacity – volume of data & users (total Capacity – volume of data & users (total

& peak)& peak) Reliability – operational vs. not Reliability – operational vs. not

operationaloperational

Nonfunctional Nonfunctional RequirementsRequirements

Continued Continued SecuritySecurity

System Value – estimated value of System Value – estimated value of system & datasystem & data

Access Control – who can access whatAccess Control – who can access what Encryption/Authentication – protection Encryption/Authentication – protection

of data across networks/Internetof data across networks/Internet Virus Control – control spread of virusesVirus Control – control spread of viruses

Nonfunctional Nonfunctional RequirementsRequirements

Continued Continued Cultural & PoliticalCultural & Political

Multilingual – language(s) of host Multilingual – language(s) of host countrycountry

Customization – user-defined fields & Customization – user-defined fields & formatsformats

Unstated Norms – use of local date, Unstated Norms – use of local date, currency, measurement formats & currency, measurement formats & labelslabels

Legal – abiding by host country(s) lawsLegal – abiding by host country(s) laws

System SpecificationSystem Specification

Document that describes the HW & Document that describes the HW & SW needed to support the systemSW needed to support the system

Three main steps to create:Three main steps to create:1.1. List all HW neededList all HW needed

2.2. Describe minimum requirements for Describe minimum requirements for each piece of HWeach piece of HW

3.3. List SW to run on each piece of HWList SW to run on each piece of HW