Good Evening! INT1005 Introduction to Computer Systems Ulrich - - PowerPoint PPT Presentation

Good Evening! INT1005 Introduction to Computer Systems

Ulrich Werner

Chapter 11

Information and Data Management

Discovering Computers

Technology in a World of Computers, Mobile Devices, and the Internet

Databases, Data, and Information

Database

• Collection of

data organized in a manner that allows access, retrieval, and use of that data Data

• Collection of

unprocessed items

• Text
• Numbers
• Images
• Audio
• Video

Information

• Processed data
• Organized
• Meaningful
• Useful

Databases, Data, and Information

• Database software, often called a database

management system (DBMS), allows users to:

Create a computerized database Add, modify, and delete data Sort and retrieve data Create forms and reports from the data

Databases, Data, and Information

• Data integrity reflects the quality of the data

– The more errors the data contains, the lower its integrity – Data integrity is important because computers and people use information to make decisions and take actions

Databases, Data, and Information

• Valuable information should have the following

characteristics:

Accurate Accurate Verifiable Verifiable Timely Timely Organized Organized Accessible Accessible Useful Useful Cost‐effective Cost‐effective

The Hierarchy of Data

Databases, Data, and Information

• Common data types include:

Text Number AutoNumber Currency Date Memo Yes/No Hyperlink Object Attachment

File Processing Versus Databases

Database Management Systems

• A data dictionary contains data about each file in the

database and each field in those files

Database Management Systems

• A DBMS provides several tools that allow users and

programs to retrieve and maintain data in the database

Query language Query language Query by example Query by example Form Form Report writer Report writer

Database Management Systems

• A query language consists of simple, English‐like statements that

allow users to specify the data to display, print, store, update, or delete

• Structured Query Language (SQL) is a popular query language that

allows users to manage, update, and retrieve data

• Many DBMSs provide tools to guide nontechnical users through

the steps of creating a query

Database Management Systems

Database Management Systems

• A form is a window on the screen that provides areas for

entering or modifying data in a database

• A report writer allows users to design a report on the

screen, retrieve data into the report design, and then display or print the report

Database Management Systems

A DBMS provides means to ensure that only authorized users access data

• Access privileges
• Principle of least privilege policy

Database Management Systems

• A DMBS provides a variety of techniques to restore the

database to a usable form in case it is damaged or destroyed

Backup Backup Log Log Recovery utility Recovery utility Continuous backup Continuous backup

Relational, Object‐Oriented, and Multidimensional Databases

• A relational database

stores data in tables that consist of rows and columns

– Each row has a primary key – Each column has a unique name

• A relationship is a link

within the data

Relational, Object‐Oriented, and Multidimensional Databases

• An object‐oriented database (OODB) stores data in
• bjects
• Examples of applications appropriate for an object‐
• riented database include:

Media database CAD database

Relational, Object‐Oriented, and Multidimensional Databases

• A multidimensional

database can store data in more than two dimensions

• f data

– Sometimes known as a hypercube – Can consolidate data much faster than a relational database

• A data warehouse is a huge

database that stores and manages the data required to analyze historical and current transactions

Web Databases

• The web offers information about:

Jobs Jobs Travel Travel Destinations Destinations Television programming Television programming Photos Photos Movies Movies Videos Videos Weather Weather Sporting events Sporting events Legislative information Legislative information

Database Administration

Database analysts and administrators are responsible for managing and coordinating all database activities Database analysts and administrators are responsible for managing and coordinating all database activities

Database Analyst (DA) Decides on proper placement of fields, defines data relationship, and identifies users’ access privileges Database Administrator (DBA) Creates and maintains the data dictionary, manages security of the database, monitors the performance of the database, and checks backup and recovery procedures

Information Systems in the Enterprise

• An information system is a set of hardware, software,

data, people, and procedures that work together to produce information

Information Systems in the Enterprise

• Enterprise Resource Planning (ERP) integrates MRP with

the information flow across an organization to manage and coordinate the ongoing activities of the enterprise, including product planning, manufacturing and distribution, accounting and finance, sales, human resources, and customer support

Information Systems in the Enterprise

• A document management system (DMS) allows for

storage and management of a company’s documents, such as word processing documents, presentations, and spreadsheets

• A content management system (CMS) enables and

manages the publishing, modification, organization, and access of various forms of documents and other files, including media and webpages, on a network or the web

Information Systems in the Enterprise

• A transaction processing system (TPS) is an information

system that captures and processes data from day‐to‐day business activities (OLTP = online transaction processing)

Information Systems in the Enterprise

• A management information system (MIS) is an information system

that generates accurate, timely, and organized information, so that managers and other users can make decisions, solve problems, supervise activities, and track progress

Information Systems in the Enterprise

• A decision support system (DSS) helps users analyze

information and make decisions

Information Systems in the Enterprise

• An expert system is an information system that captures

and stores the knowledge of human experts and then imitates human reasoning and decision making

Break time, Ladies & Gentlemen 

Chapter 12

Information Systems and Program Development

Discovering Computers

Technology in a World of Computers, Mobile Devices, and the Internet

System Development

System development is a set of activities used to build an information system

System development activities are grouped into phases, and is called the system development life cycle (SDLC)

System Development

• System development should follow three general

guidelines:

Group activities or tasks into phases Group activities or tasks into phases Involve users Involve users Define standards Define standards

System Development

• Project management is the process of planning,

scheduling, and then controlling the activities during system development

• To plan and schedule a project efficiently, the project

leader identifies the following elements:

Project scope Required activities Time estimates for each activity Cost estimates for each activity Order of activities Activities that can take place at the same time

System Development

Popular tools used to plan and schedule the time relationships among project activities are Gantt and PERT charts

System Development

• Feasibility is a measure of how suitable the development
• f a system will be to the organization

Operational feasibility Schedule feasibility Technical feasibility Economic feasibility

Plus legal feasibility = TELOS

System Development

• Documentation is the collection and summarization of

data, information, and deliverables.

• Maintaining up‐to‐date documentation should be an
• ngoing part of system development.

System Development

• During system development, members of the project

team gather data and information using several techniques

Review documentation Observe Survey Interview JAD Sessions Research

System Development

• The planning phase for a project begins when the

steering committee receives a project request

• Four major activities are performed:

Review and approve the project requests Review and approve the project requests Prioritize the project requests Prioritize the project requests Allocate resources Allocate resources Form a project development team Form a project development team

System Development

• The system proposal assesses the feasibility of each

alternative solution

• The steering committee discusses the system proposal

and decides which alternative to pursue

Modify existing system Buy retail software Use web apps Build custom software Outsource

System Development

• The design phase consists of two major activities

Acquire hardware and software Develop all of the details of the new or modified information system

System Development

• To acquire the necessary hardware and software:

Identify technical specifications Solicit vendor proposals Test and evaluate vendor proposals Make a decision

System Development

• The next step is to develop detailed design specifications

Database design Input and output design Program design

Data Modeling and Database Models

When building a database, consider:

– Content: What data should be collected and at what cost? – Access: What data should be provided to which users and when? – Logical structure: How should data be arranged so that it makes sense to a given user? – Physical organization: Where should data be physically located?

Data Modeling

Building a database requires two types of designs:

– Logical design: abstract model of how the data should be structured and arranged to meet an organization’s information needs – Physical design: starts from the logical database design and fine‐tunes it for performance and cost considerations

Data Modeling

Connecting logical and physical model:

• Planned data redundancy to improve performance
• Data model: diagram of data entities and their

relationships

• Entity‐relationship (ER) diagrams: data models that

use basic graphical symbols to show the organization

• f and relationships between data

Simplified: ER Diagram for a library

Customer Nr. Customer-Nr. Name Address Author-Nr. Name Author written Customer Book Book-Nr. Title borrowed Date

System Development

• A prototype (proof of concept) is a working model of the

proposed system’s essential functionality

• Computer‐aided software engineering (CASE) tools are

designed to support one or more activities of system development

System Development

• The purpose of the implementation phase is to construct

the new or modified system and then deliver it to users

Develop programs and apps Develop programs and apps Install and test the new system Install and test the new system Train users Train users Convert to the new system Convert to the new system

System Development

• Various tests should be performed on the new system

Unit test

• Verifies that

each individual program or

• bject works

by itself

• Verifies that

each individual program or

• bject works

by itself Systems test

• Verifies that

all programs in an application work together properly

• Verifies that

all programs in an application work together properly Integration test

• Verifies that

an application works with

• ther

applications

• Verifies that

an application works with

• ther

applications Acceptance test

• Checks the

new system to ensure that it works with actual data

• Checks the

new system to ensure that it works with actual data

System Development

• Training involves showing users exactly how they will use

the new hardware and software in the system

– One‐on‐one sessions – Classroom‐style lectures – Web‐based training

System Development

• One or more of four conversion strategies can be used to

change from the old system to the new system

– Direct conversion – Parallel conversion – Phased conversion – Pilot conversion

System Development

• The purpose of the maintenance and monitoring phase

is to provide ongoing assistance for an information system and its users after the system is implemented

Perform maintenance activities Monitor system performance Assess system security

Have a nice evening!