MELJUN CORTES Overview of Software

Overview of Software

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• Computer programs: sequences of instructions for the computer

• Documentation: describes program functions

• Systems software: coordinates the activities of hardware and programs

• Application software: helps users solve particular problems

MELJUN CORTESMELJUN CORTES

Systems Software

Application Software

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• Give users the ability to solve problems and perform specific tasks

• Interact with systems software; systems software then directs the hardware to perform tasks

• Proprietary software: unique program for a specific application, usually developed and owned by a single company

• Off-the-shelf software: existing software program that can be purchased

• Customized package

Personal Application Software

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Serves the needs of an individual user

Includes personal productivity softwareEnables users to improve their personal effectiveness

Personal Application Software (continued)

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Table 2.7: Examples of Personal Productivity Software

Personal Application Software (continued)

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Table 2.7: Examples of Personal Productivity Software (continued)

Workgroup Application Software

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Workgroup application software: support teamwork, whether people are in the same location or dispersed around the world

Groupware: software that helps groups of people work together more efficiently and effectively

Enterprise Application Software

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Software that benefits an entire organization

Enterprise resource planning (ERP) software: programs that manage a company’s vital business operations for an entire multisite, global organization

Enterprise Application Software (continued)

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Table 2.10: Examples of Enterprise Application Software

Information, Decision Support,and Specialized Software

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Used in businesses of all sizes and types to increase profits or reduce costs

Available in every industryExample: analysis to increase the cure rate for cancer

Data Management

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Without data and the ability to process it, an organization could not successfully complete most business activities

Data consists of raw factsFor data to be transformed into useful information, it must first be organized in a meaningful way

The Hierarchy of Data

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• Bit (a binary digit): a circuit that is either on or off

• Byte: eight bits• Character: basic building block of information– Each byte represents a character – Can be an uppercase letter, lowercase letter,

numeric digit, or special symbol• Field: typically a name, number, or combination

of characters that describes an aspect of a business object or activityRecord: a collection of related data fields

• File: a collection of related records• Database: a collection of integrated and

related files• Hierarchy of data: bits, characters, fields,

records, files, and databases

The Hierarchy of Data

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Figure 3.1: The Hierarchy of Data

Data Entities, Attributes, and Keys

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• Entity: a generalized class of people, places, or things (objects) for which data is collected, stored, and maintained

• Attribute: characteristic of an entity • Data item: value of an attribute• Key: field or set of fields in a record

that is used to identify the record• Primary key: field or set of fields that

uniquely identifies the record

Data Entities, Attributes, and Keys

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Figure 3.2: Keys and Attributes

The Database Approach

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• Traditional approach to database management– separate data files are created for each

application• Results in data redundancy (duplication)• Data redundancy conflicts with data integrity

• Database approach to database management:–pool of related data is shared by multiple

applications• Significant advantages over traditional approach

The Database Approach to Data Management

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Figure 3.3: The Database Approach to Data Management

The Database Approach Advantages

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Table 3.1: Advantages of the Database Approach

The Database Approach (continued)

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Table 3.1: Advantages of the Database Approach (continued)

The Database Approach Disadvantages

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Table 3.2: Disadvantages of the Database Approach

Data Modeling and the Relational Database Model

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When building a database, consider:Content: What data should be

collected, at what cost?Access: What data should be provided

to which users and when?Logical structure: How should data be

arranged to make sense to a given user?

Physical organization: Where should data be physically located?

Data Modeling

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• Building a database requires two types of designs– Logical design• Abstract model of how data should be structured

and arranged to meet an organization’s information needs– Data model: a diagram of data entities and their

relationships– Entity-relationship (ER) diagrams: data

models that use basic graphical symbols to show the organization of and relationships between data

– Physical design• Fine-tunes the logical database design for

performance and cost considerations

ER diagram for a Customer Order Database

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ER diagram Showing the Relationship between the Manager, Department and

Project

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Implementing the Relational Database Model

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data elements are placed in two-dimensional tables (relations), which are the logical equivalent of files

Each row of a table represents a data entity

Columns of the table represent attributes

The domain of the database model consists of all of the allowable values for data attributes i

The Relational Database Model

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Figure 3.5: A Relational Database Model

Manipulating Databases

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Selecting: eliminates rows according to criteria

Projecting: eliminates columns in a tableJoining: combines two or more tablesLinking: relates or links two or more tables

using common data attributes

Manipulating Data (continued)

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Figure 3.7: Linking Data Tables to Answer an Inquiry

Database Management Systems (DBMS)

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• Interface between:–Database and application programs –Database and the user

• Creating and implementing the right database system ensures that the database will support both business activities and goals

• DBMS: a group of programs used as an interface between a database and application programs or a database and the user

Overview of Database Types

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• Flat file–Simple database program whose records have

no relationship to one another• Single user–Only one person can use the database at a

time–Examples: Access, FileMaker, and InfoPath

• Multiple user–Allows dozens or hundreds of people to access

the same database system at the same time–Examples: Oracle, Sybase, and IBM

Distributed Databases

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Distributed databaseData may be spread across several

smaller databases connected via telecommunications devices

Corporations get more flexibility in how databases are organized and used

Replicated databaseHolds a duplicate set of frequently

used data

Telecommunications

Basic Concepts of Telecommunications

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• Telecommunications: electronic transmission of signals for communications

• Computer network: communications media, devices, and software needed to connect two or more computer systems or devices

• Network types: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and international networks

The Internet

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Internet: collection of interconnected networks, all freely exchanging information

Internet Protocol (IP): communication standard that enables traffic to be routed from one network to another as needed

Uniform Resource Locator (URL): an assigned address on the Internet for each computer

Business Networks

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Intranet: internal corporate network built using Internet and World Wide Web standards and protocols

Extranet: network based on Web technologies that links selected resources of a company’s intranet with its customers, suppliers, or other business partners

Systems Development

An Overview of Systems Development

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Managers and employees in all functional areas work together in a business information system

Users help and often lead the way with development process

Participants in systems development: Determine when a project failsAre critical to systems development success

Participants in Systems Development

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• Development team consists of the following:– Project managers: coordinate system

development effort– Stakeholders: directly or indirectly benefit from

the project– Users: interact with the system regularly– Systems analysts: analyze and design business

systems– Programmers: modify or develop programs to

satisfy user requirements– Various support personnel: specialists, vendors

Information Systems Planning and Aligning Corporate and IS

Goals

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Information systems planning: translating strategic and organizational goals into systems development initiatives

Aligning organizational goals and IS goals is critical for any successful systems development effort

Determining whether organizational and IS goals are aligned can be difficult

Information Systems Planning and Aligning Corporate and IS Goals (continued)

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Figure 8.2: Information Systems Planning

Systems Development Life Cycles

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• The systems development process is also called a systems development life cycle (SDLC)

• Common SDLCs– Prototyping– Rapid application development (RAD) Systems • development approach that employs tools, techniques,

and methodologies designed to speed application development

– End-user development any systems • development project in which the primary effort is

undertaken by a combination of business managers and users

Systems Development Activities

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• Systems investigation:– problems and opportunities are identified and

considered in light of the goals of the business• Systems analysis: – study of existing systems and work processes to

identify strengths, weaknesses, and opportunities for improvement

• Systems design: – defines how the information system will do what it

must do to obtain the problem solution• Systems implementation: – creation or acquisition of various system components

detailed in the systems design, assembling them, and placing the new or modified system into operation

• Systems maintenance and review: – ensures that the system operates as intended and

modifies the system so that it continues to meet changing business needs