DSS Architecture MBA 572 Craig K. Tyran Fall 2002

A. Game Plan Introduction Computer hardware Type of platforms Stand alone Centralized system Client/Server processing

B. Computer Architecture Refers to the way that the information system Is physically laid out How tasks are allocated How parts of system interact with each other How system interacts with the outside world Goals Ease of use Compatibility of systems Expandability of systems

C. Computer Hardware When addressing the topic of “architecture” … It may be useful to get a quick refresher on computer hardware and operating system terms … Rank the following from largest to smallest: Micro computer Mainframe Workstation PDA Supercomputer

C. Computer Hardware (cont.) Supercomputer Most processing power Common applications: Large simulation models of real-world phenomena Mainframe Computer “Big iron” Used in large corporations for centralized data processing and maintaining large databases Multi-user access Recent application: Large servers for WWW systems Vendors include IBM, Amdahl, Hitachi

C. Computer Hardware (cont.) 4. Workstation Desktop machines “PC on steroids” Provide very high-speed calculations and high-resolution graphic displays Applications: engineering, stock market analysts, software development, animated movies Vendors include Sun Microsystems, Silicon Graphics

C. Computer Hardware (cont.) 5. Microcomputer Desktop PC, Mac Often single-user, but can be used as servers Vendors?? 6. Personal digital assistant (PDA) Hand-held “palmtop” computer Wireless capabilities: WWW and E-mail Vendors: Palm, Handspring, Compaq

D. Operating System Software 1. Operating system (OS) Supervises the overall operation of computer Interacts with application software Manages the operation of computer hardware Intermediary between application SW and computer HW Application Software Operating System

D. Operating System (cont.) Functions: Examples Processor Management Multitasking Memory management Processes require memory OS  Allocates memory across processes Storage management Allows users to save, delete, access, & organize files stored in secondary storage OS  Keeps track of physical location and characteristics of files User interface This what the user sees Most people prefer a “GUI” interface Example???

E. Platforms Refers to the combined hardware/ operating system environment that supports applications Common platform types include Free standing user system Central corporate system Client-server system

D. “Free Standing” Platform DSS is “self contained” -- does not access any other computers or databases e.g., PC running an Excel workbook with a list of data Pros Can be less complex with respect to sharing/hooking up with other systems User can have complete control Good development tools available (e.g., Excel) Cons No access to other systems imposes limitations e.g., can’t access company database  not good for data-oriented DSS Sharing results with others can be more difficult

E. “Central Corporate” Platform A very well known information “architecture” Example: Mainframe environment Many people log into one big computer to use DSS Pros Large platform can support intensive processing And … access to organizational database Centralized location can help with updates Cons Responsiveness may be an issue e.g., other system operations may have priority User may have to wait more to get DSS developed or upgraded User interface to larger platform may not be easy for end users

F. “Client-Server” Platform 1. Client/server environment Computers are networked together Processing/storage is shared across two or more computers Very popular architecture Have you ever used a client/server network???

F. Client/Server Processing 2. Division of labor  “Smart” client and a “smart” server 3. Role of client User interface (“front end”) May also perform processing Example of a simple client WWW program that accepts sales orders Capture input, display output

F. Client/Server Processing 4. Role of server “Back end” Manage the data Some or most of the processing for a business task may be handled at the server Example See figure

Client/Server Implementation for Pay Raises

F. Client/Server Processing (cont.) 5. Server computers ??? PCs, work stations, mainframe computers 6. Types of client/server models The “models” vary with regard to division of labor Key variations: Where does the presentation processing happen? Where does the logic processing happen? Where does the data management happen?

Client/Server Models

F. Client/Server Processing (cont.) 7. Pros User only needs to learn the client interface Can be more user friendly e.g., data entry can be done using MS Windows interface instead of an unfamiliar mainframe interface Can have “thinner” clients “Thinner”  Less computer processing Do not need all database or application software at client Save $$ since it is not necessary to buy expensive desktops computers If computers share the labor, then don’t need to download as much data over the network Less data transfer  better network performance

F. Client/Server Processing (cont.) 8. Cons Can take extra time/expertise to ensure coordination between server and client Can be more difficult/costly ($$$) to manage Potential security issues involving the network