System Concepts & Components

Dr. Dania Bilal

IS582

Spring 2009

Definition

• System– Hardware

• Physical parts of computer

– Software• Programs: Execute set of instructions

– Has interrelated set of components – There is interaction among components– Has interaction with world outside of it

(environment)

Type of Software

• Application software– Set of computer programs written to perform

specific task– Word, Execl, PowerPoint– Runs on top of operating software (Windows)

• Operating software/system– Computer program allows computer to work

System Fundamentals

• Decomposition– Breaking system into smaller components based on

functions

• Modularity– Results from decomposition

• Coupling– Independence of modules ( on each other (operate

concurrently and/or independently)

• Cohesion – Extent of subsystem (can be a module or submodule)

in performing single function or task)

System Characteristics

• Purpose• Components (modules, submodules)• Boundary (limits separate system from

other systems)• Environment (Whatever outside boundary,

e.g., users)• Interfaces (Intermediary b/w user

(environment) & system)• Constraints (capacity, speed, capabilities)

Types of IS

• Transaction Processing Systems (TPS)

• Management Information Systems (MIS)

• Decision Support Systems (DSS)

• Expert Systems

• Information Retrieval Systems (IRs)

TPS

• Designed to handle a large volume of transactions to keep track of processes – Billing, payroll, order tracking and processing,

accounts payable and receivable, securities, trading, etc.

• Purposes– Improve accuracy, productivity, efficiency– Speed up processes

MIS

• Takes raw data from one or more TPS

• Analyzes data & provides reports for activities that can be helpful to managers for decision making

DSS

• Uses information from raw data, documents, business/graphical models to identify and solve problems and make decisions.

• Provides projections based on data in hand or assumptions

• Has 3 parts: Database, model base, user interface

• Mathematical rules provide interrelationships among different data– Used to predict future data or find best solutions to

problems

ES

• Knowledge of experts is captured in a computer to solve problems

• Based on Artificial Intelligence to recognize, formulate, solve problems, and learn from experience

• Software are called shells

• Not successful in all disciplines– Most fruitful in medicine for diagnosis

IRs

• Store and search for documents, information within documents, and metadata about documents

• Use standards and protocols for storage and retrieval based on specific search algorithms

• Types– Bibliographic (ex: library online catalog)– Numeric (statistical IR)– Combined

Library Automated System

• Composed of software and hardware• Software environments:

– Off-the-shelf (turnkey) - unshared • Independent

– Off-the-shelf (turnkey) - shared• Union catalog• Consortia

– Open source (independent or shared)– In-house

• Based on open source or • Program totally developed onsite

System Functionality

• Modular– Module(s) that operate independently and but

not concurrently

• Integrated (ILS)– Modules that operate independently and

concurrently– Share common database

System Interfaces

• Windows-based– Based on Windows operating system

• Web-based– Requires WWW browser for use

• Character-based (DOS)– Obsolete in many environments

ILS Modules & Functions

Modules

• OPAC (Online Public Access Catalog)• Cataloging

– Authority control

• Circulation• Inventory control• Acquisitions• Serials Management• Interlibrary loan• Media booking• Management (reports, database indexing)• Maintenance

Function of Each Module

StudentsBe prepared to discuss the function of each

module. Here are some questions to think about:• What is the purpose of OPAC?• What is OPAC based on? (what makes the

records appear the way they do)?• What is the Circulation module based on?• Can the OPAC module exist without the

Cataloging module?• Can the circulation module exist with a

cataloging module?