INFS 6225 Object-Oriented Systems Analysis & Design Chapter 11: Physical Architecture Layer Design

Architecture Design Plan for Hardware, Software, & Infrastructure Plan for Hardware, Software, & Infrastructure Part of the System Architecture Layer Part of the System Architecture Layer Designed based on business needs specified in the Analysis Phase 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. Fat Client – more application logic on local PC 2. Thin Client – less application logic on local PC

Tiered Architecture All Client PCs count as one tier All Client PCs count as one tier Each Server PC counts as one tier Each Server PC counts as one tier Four-tier client-server architecture >>

Network Models Shows major components (e.g., servers, communication lines, networks) & their geographic location Shows major components (e.g., servers, communication lines, networks) & their geographic location Show complexity of system Show complexity of system Show how components fit together Show how components fit together No standards for creating Network Models No standards for creating Network Models

Nonfunctional Requirements Operational – specifies operating environment Operational – specifies operating environment Performance – response time, capacity, & reliability Performance – response time, capacity, & reliability Security – protection from disruption & data loss Security – protection from disruption & data loss Cultural & Political –specific requirements of host countries Cultural & Political –specific requirements of host countries

Nonfunctional Requirements Continued Operational Operational Technical – HW, SW, & NW specifications Technical – HW, SW, & NW specifications System Integration – interface w/ other systems System Integration – interface w/ other systems Portability – operation in other environments Portability – operation in other environments Maintainability – adapting to changing business requirements Maintainability – adapting to changing business requirements

Nonfunctional Requirements Continued Performance Performance Speed – response time Speed – response time Capacity – volume of data & users (total & peak) Capacity – volume of data & users (total & peak) Reliability – operational vs. not operational Reliability – operational vs. not operational

Nonfunctional Requirements Continued Security Security System Value – estimated value of system & data System Value – estimated value of system & data Access Control – who can access what Access Control – who can access what Encryption/Authentication – protection of data across networks/Internet Encryption/Authentication – protection of data across networks/Internet Virus Control – control spread of viruses Virus Control – control spread of viruses

Nonfunctional Requirements Continued Cultural & Political Cultural & Political Multilingual – language(s) of host country Multilingual – language(s) of host country Customization – user-defined fields & formats Customization – user-defined fields & formats Unstated Norms – use of local date, currency, measurement formats & labels Unstated Norms – use of local date, currency, measurement formats & labels Legal – abiding by host country(s) laws Legal – abiding by host country(s) laws

System Specification Document that describes the HW & SW needed to support the system Document that describes the HW & SW needed to support the system Three main steps to create: Three main steps to create: 1. List all HW needed 2. Describe minimum requirements for each piece of HW 3. List SW to run on each piece of HW