Modern Computer Systems and
Applications
Lecture 2
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Elements of Systems Design
To pics
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Elements of Design
Inputs for System Design
Design and Integrate the Network
Design the Application Architecture
Design the User Interfaces
Design the System Interfaces
Prototype for Design Details
Deployment Environment
Software Application Functions
Internet and Web-Based Application Architecture
Middleware
Elements of Design
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Design is process of describing, organizing, and structuring system
components at architectural design level and detailed design level
 Focused on preparing for construction
 Like developing blueprints
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Three questions
 What components require systems design?
 What are inputs to and outputs of design process?
 How is systems design done?
Components Requiring Systems Design
In puts for System Design
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Design
o Converts
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functional models from analysis into models
that represent the solution
Focused on technical issues
Requires less user involvement than analysis
Design may use structured or OO approaches
o Database can be relational, OO, or
o User interface issues
hybrid
Analysis versus Design
Traditional Structured and Object-Oriented Models
SDLC Phases with Design Phase Activities
Design Phase Activities and Key Questions
Design and Integrate the Network
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Network specialists establish network based on strategic plan
Project team typically integrates system into existing network
Technical requirements have to do with communication via networks
Technical issues handled by network specialists
Reliability, security, throughput, synchronization
Design the Application Architecture and
Software
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Specify how system use cases are carried out
Described during system analysis as logical models of system activities
After design alternative is selected, detailed computer processing is designed as physical models
Approach varies depending on development and deployment environments
Design the User Interfaces
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User interface quality is critical aspect of system
Design of user interface defines how user interacts with system
o GUI – windows, dialog boxes, mouse interaction
o Sound, video, voice commands
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To user of system, user interface is the system
User interface specialists – interface designers, usability consultants, human factors engineers
Des ign the S ystem Inte rfaces
 System interfaces enable systems to share and exchange information
o Internal organization systems
o Interfaces with systems outside organization
o New system interfaces with package application that
organization has purchased and installed
 System interfaces can be complex
 Organization needs very specialized technical skills to work on these interfaces
Design and Integrate the Database
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System analysis data model used to create physical database model
Collection of traditional computer files, relational databases, and/or object-oriented databases
Technical requirements, such as response times, determine database performance needs
Design work might involve
o Performance tuning
o Integration between new and existing databases
Prototype for Design Details
 Continue to create and evaluate prototypes during design phase
 Prototypes confirm design choices
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Database
Network architecture
Controls
Programming environment
 Rapid application development (RAD) design prototypes evolve into finished system
Design and Integrate the System Controls
 Final design activity to ensure system has adequate safeguards (system controls) to protect
organizational assets
 Controls are needed for all other design activities
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User interface – limit access to authorized users
System interface – protect from other systems
Application architecture – record transactions
Database – protect from software/hardware failure
Network design – protect communications
Network Design
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Integrate network needs of new system into existing network infrastructure
Describe processing activity and network connectivity at each system location
Describe communications protocols and middleware that connects layers
Ensure that network capacity is sufficient
o Data size per access type and average
o Peak number of access per minute or hour
Computer Networks
 Set of transmission lines, specialized hardware, and communication protocols
 Enables communication among different users and computer systems
 Local area network (LAN) less than one kilometer long – connects computers within single
building
 Wide area network (WAN) over one kilometer long – implies much greater, global, distances
 Router – directs information within network
A Possible Network Configuration for RMO
The Internet, Intranets, and Extranets
 Internet – global collection of networks that use TCP/IP networking protocols
 Intranets
o Private networks using same TCP/IP protocols as the Internet
o Limited to internal users
 Extranets
o Intranets that have been extended outside the organization
Network Diagram for RMO
Customer Support System
Deployment Environment
 Deployment environment definition bridges analysis and design
o Hardware
o System software
o Networking
 Common deployment environments in which system will operate
 Related design patterns and architectures for application software
Application Architecture
 Complex hardware/networks require more complex software architectures
 There are commonly used approaches (patterns) for application architecture
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Client/server architecture
Three-layer client/server architecture
Web services architecture
Internet and Web-based application architecture
Software Application Functions
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Presentation logic (i.e. HCI)
Application logic (i.e. the processing of business rules processing)
Data access logic (i.e. the processing required to access data – database queries in
SQL)
Data storage (i.e. data files)
There are several alternatives for the processing environment:
o Centralized systems
o Distributed computing
Centralized systems
 Prior to the early 1970’s there was only one technological environment – the
mainframe computer system at a central location
 The only options focused around kinds of input/output (e.g., keypunch, key-to-tape,
or interactive input using video display terminal) and whether input/output devices
would be placed in remote locations
 Although they are no longer the preferred platform for deploying ISs, they are still
widely used as a subsystem of a larger, sometimes distributed information system or
for large-scale batch processing applications (e.g., banking, insurance, government,
etc.) where:
o Some input transactions don’t need to be processed in real time
o On-line data-entry personnel can be centrally located
o Large numbers of periodic outputs are produced by the system
There are three types of centralized systems:
single, clustered and multicomputer architectures
Single Computer Architecture
 Places all information system resources on a single computer system and its directly
attached peripheral devices
 Users interact with the system via simple input/output devices directly connected to
the computer
 Requires all users be located near the computer
 All 4 software application functions are realized on a mainframe computer (server
host) – server-based architecture
Advantage:
• Simplicity of maintenance: relatively easy to design, build and operate
Disadvantage:
• The capacity limits make single computer impractical or unusable for large ISs: cannot
provide all the required processing, data storage, and data retrieval tasks. However,
many systems require more computing power than one single machine can provide (a
clustered or multicomputer architecture is required)
Single-Computer, Clustered, and
Multicomputer Architectures
Server-based Architecture
Clustered Architecture
 Clustered architecture is a group (or cluster) of computers of the same type that
have the same operating environment and share resources
 Computers from the same manufacturer and model family are networked together
 Application programs may be executed on any machine in the cluster without
modification due to similar hardware and operating systems
 Cluster acts like a single large computer system (program movement and access to
resources on other machines occur quickly and efficiently due to rapid and direct
communication at the operating system level)
 Often one computer may act as entry point and the others function as slave
computers
Distributed Architecture
 Distributes system across several computers and locations – distributed computing
 Relies on communication networks for geographic connectivity
 Client/server architecture dominant model for distributed computing
Client/Server Architecture
The dominant architectural model for distributing information resources
 Two-tire architecture divides the information system processes into
two classes:
o Server: manages system resources and provides access to those resources and services
to other computers on the network
o Client computer: uses communication interface to requests services from other
computers on the network
 Computer software that implements communication protocols on the
network is called middleware
 Advantage – deployment flexibility
Location, scalability, maintainability
 Disadvantage – complexity
Performance, security, and reliability
Interaction Among Multiple Clients and a Single Server
Client/Server Architecture: shared printer
“Fat” Client Architecture
“Fat” Server Architecture
Three-Layer Client/Server Architecture
 The data layer is a layer on a client-server configuration that manages stored data
implemented as one or more databases
 The business logic layer contains the programs that implement the rules and
procedures of business processing (or program logic of the application)
 The view layer contains the user interface and other components to access the
system (accepts user input, and formats and displays processing results)
 This approach is called tree-layer architecture
o The IS divided into three layer is relatively easy to distribute and replicate
across a network (interactions among the layers are always have a form of
either request or response)
o It makes the layer relatively independent of one another, thus they can be
placed on different computer systems with network connections and
middleware serving
Three-Layer Architecture Software Application
Functions
Four-Tier Architecture
Internet and Web-Based Application Architecture
 Web is complex example of client/server architecture
 Can use Web protocols and browsers as application interfaces
 Benefits
o Accessibility
o Low-cost communication
o Widely implemented standards
N-Layer Architecture
Four-Tier Architecture
Internet and Web-Based Application Architecture
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Web is complex example of client/server architecture
Can use Web protocols and browsers as application interfaces
Benefits
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Accessibility
Low-cost communication
Widely implemented standards
Negative Aspects of
Internet Application Delivery
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Breaches of security
Fluctuating reliability of network throughput
Throughput can be limited
Volatile, changing standards
Web Services Architecture
 A client/server architecture
 Packages software functionality into server processes (“services”)
 Makes services available to applications via Web protocols
 Web services are available to internal and external applications
o Developers can assemble an application using existing Web services
Web Services Architecture (continued)
Mid dleware
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Aspect of distributed computing
Connects parts of an application and enables requests and data to pass between them
Transaction process monitors, object request brokers (ORBs), Web services directories
Designers reply on standard frameworks and protocols incorporated into middleware
INTRODUCTION TO COMPUTER APPLICATION
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Business and Information Technology Education
Family and Consumer Sciences Education
Marketing Education
Technology Education
Trade and Industrial Education
Business and Information
Technology Education
 Principles of Business
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Business in a Changing World
The Consumer’s Impact on Business
Leadership/Communication Skills
Taxes and Spending
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Money Management
Banking
Credit
Savings & Investments
Insurance
Careers in Business & Marketing
 The Internet
 Search tools and search methods
 Electronic communication and online safety
 Word
 Business documents
○ Resume, business letter, memo, agenda, minutes, itinerary, research report,
table of contents, news/press release
 Business publications
○ Business card, letterhead stationery, flyer, brochure, newsletter
 Excel
 Spreadsheets used in business
 Charts/graphs used in business
 Databases
 Tables used in business
 Queries, forms, and reports used in business
 PowerPoint
 Understanding and developing multimedia business
presentations
 Solution Development Process
 Coding Structure, Decision making, Looping
 Programmer defined modules
 Use of Arrays
○ Error-Handling Logic
○ Data Storage and Access
○ Use of Databases
○ Develop Projects using Systems Development Life Cycle
Family and Consumer Sciences Education
Marketing (ME) Courses
 Small Business Entrepreneurship
 Marketing
 Sports and Entertainment Marketing
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Business Plan is , major goal (30 pages)
Traits Required
Ethics/Responsibilities
Ownership & Laws
Financial Options
Marketing
Management
Business Risks
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Site Selection
Product Selection
Employee Training
Business Image
Accounting Principles
o Income Statement
o Balance Sheet
o Sales Projections
 Many parents tell us they want to take the course!
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Site Selection
Product Selection
Employee Training
Business Image
Accounting Principles
o Income Statement
o Balance Sheet
o Sales Projections
 Many parents tell us they want to take the course!
 Marketing Mix
o Price, Product, Promotion, & Place
 Economic Principles
○ Factors of Production
○ Economic Utilities
○ Supply & Demand and Elasticity theory
○ Economic Systems
 Business ownership options and laws governing each
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Communication Skills
Selling Techniques – B2B vs. Consumer
Promotional Strategies
Visual Merchandising
Advertising Campaign
Marketing Career Options
 Specific application of marketing theories to the billion dollar
world of sports and entertainment industry.
 Sponsorship Marketing
 Event Planning
 Stadium Development
 Competitive Event in DECA