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 Students Be 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?