Chapter 14 : Enterprise Computer

Chapter 14 : Enterprise Computer

• Enterprise computing involves the use of computers in networks,such as LANs and WANs, or a series of interconnected networks that encompass a variety of different operating systems,protocols, and network architectures
• Types of enterprises:-Retail, -Manufacturing, -Service, -Wholesale, -Government, -Educational, -Transportation.
• Most traditional enterprises are organized in a hierarchical manner
• In an enterprise , users typically fall into one of four categories

Executive Management Middle Management Operational Management Non management Employees Enterprise information is the information is the information gathered in the ongoing operations of an enterprise-sized organization - Business intelligence -Business process management -Business process automation Managers coordinate resources by performing four activities -Planning -Organizing -Leading -Controlling Information System in the Enterprise An information system is a set of hardware,software,data,people, and procedures that work together to produce information Functional units within an enterprise might include -accounting and finance -human resource -engineering or product development -manufacturing -marketing -sales -distribution -customer -information technology Accounting software manages everyday transactions Billing software helps the company reconcile purchases with customer payments Financial software helps managers budget , forecast, and analyze A human resources information system(HRIS) manages one or more human resources functions Employee relationship management systems manage communication between employees and the business Computer-aided design(CAD) uses computers and special software to aid in engineering , drafting , and design Computer-aided engineering (CAE) uses computers to test product designs Computer-aided manufacturing (CAM) is the use of computers to control production equipment Computer-integrated manufacturing (CIM) uses computers to integrate the many different operations of the manufacturing process Material Requirements Planning (MRP) uses software to help monitor and control processes related to production Manufacturing Resource Planning 11 (MRP11)is an extension of MRP and also includes software that helps in scheduling A quality control system helps an organization maintain or improve the quality of its products or services A marketing information system serves as a central repository for the tasks of a marketing department sales force automation(SFA) software equips traveling salespeople with the electronic tools they need to be more productive Distribution system perform the following functions -Provide forecasting for inventory control -Manage and track shipping of products -Provide information and analysis on inventory in a warehouse Customer interaction management (CIM) software manages the day-to-day interactions with customers The information technology (IT) department makes technology decisions for the enterprise Web site management programs collect data designed to help organization make informed decisions regarding their Wed presence General purpose information systems generally fall into one of five categories -office information system -transaction processing system -management information system -decision support system -expert system Batch processing vs online transaction processing Integrated Information Systems -Customer relationship management manages information about customer,interactions with customers, past purchases and interests -Enterprise resource planning provides centralized,integrated software to help mange and coordinate ongoing activities -Content management system are information system that combine databases ,software, and procedures Enter-Wide Technologies and Methodologies Some technologies used in enterprises include -portals -data warehouses -electronic data interchange -extranets -web services -document management systems -workflow -virtual private networks -A portal is a collection of links, content, and services presented on a Web page that are interesting for a particular job function. -A data warehouse is a huge database that stores manages the data required to analyze historical and current transactions. -Web services allow businesses to create products and B2B interactions over the Internet. -A document management system (DMS) allows for storage and management of a company's documents. -A workflow is a defined process that identifies the specific set of steps involved in completing a particular project or business process. -A virtual private network (VPN) provides mobile users, vendors, and customers with a secure connection to the company network server. Virtualization and cloud Computing -Virtualization is the practice of sharing or pooling computing resources. -Server virtualization: Provides the capability to divide a physical server logically into many virtual servers. -Storage virtualization: Provides the capability to create a single logical storage device from many physical storage devices. Enterprise Hardware -Enterprise hardware allows large organizations to manage and store information and data using devices geared for: Heavy use, Maximum availability, Maximum efficiency. -RAID duplicates data and implements duplication in different ways. -Network attached storage (NAS) is a server that provides storage to users and information systems attached to the network. -A storage area network (SAN) is a high-speed network that provides storage to other servers to which it attached. -An enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company. -A blade server packs a complete computer server on a single card rather than a system unit. -A thin client is a small terminal-like computer that mostly relies on a server for data storage and processing. -The processing for a thin client usually is done on a server. High Availability, Scalability, and Interoperability -A high-availability system continues running and performing tasks for at least 99% of the time. -Scalability is a measure of how well computer hardware, software, or an information system can grow to meet increasing performance demands. -Interoperability is the ability for an information system to share information with other information systems within an enterprise. Backup Procedures -Continuous data protection provides automatic data backup whenever data is changed in an enterprise. -A disaster recovery plan is a written plan describing the steps a company would take a restore computer operations in the event of a disaster. -Contains four major components: Emergency plan, Backup plan, Recovery plan, Test plan.

Chapter 13 : Computer Programs and Programming Languages

Computer Programs and Programming Languages

• A computer program is a series of instructions that directs a computer to perform tasks. Created by a programmer using a programming language.

Low-Level Languages

• Machine language is the first generation of programming languages.
• Only language the computer directly recognizes.
• Assembly language is the second generation of programming languages.
• A source program contains the code to be converted to machine language.

Procedural language

• In a procedural language, the programmer writes instructions that tell the computer what to accomplish and how to do it. A compiler translate an entire program before executing it. An interpreter converts and executes one code statement at a time.
• The C programming language is used to write many of today's programs.
• COBOL (COmmon Business-Oriented Language) is designed for business applications, but easy to read because of the English-like statements.

Object-Oriented Programming Languages and Program Development Tools

• An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects.
• Other advantages include: Objects can be reused, Work well in a RAD environment, Programmers create applications faster.
• Java is an object-oriented programming language developed by Sun Microsystems.
• The Microsoft .NET Framework allows almost any type of program to run on the Internet or an internal business network, as well as computers and mobile devices.
• C++ is an extension of the C programming language.
• C# is based on C++ and was developed by Microsoft.
• F# combines the benefit of an object-oriented language with those of a functional language.

A visual programming language is a language that uses a visual or graphical interface for creating all source code.

• PowerBuilder is a powerful program development RAD tool.
• A 4GL (fourth-generation language) is a nonprocedural language that enables users and programmers to access data in a database.
• An application generator is a program that creates source code or machine code from a specification of the required functionality.
• A macro is a seriess of statements that instructs an application how to complete a task.
• The macro are usually created in one of two ways: Record the macro with a macro recorder, Write the macro.

Web Page Development

• HTML is a special formatting language that programmers use to format documents for display on the Web.
• XHTML is a markup language that allows Web sites to be displayed more easily on mobile devices.
• XML allows Webs developers to create customized tags and use predefined tags to display content appropriately on various devices. -WML is a subset of XML and is used to design pages for microbrowsers.
• Two application of XML are RSS 2.0 and ATOM.
• Web browsers can execute short programs to add interactive elements to Web pages.
• Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages.
• Web 2.0 allows Web sites to provide a means for users to: Share personal information, Allow users to modify Web site content, Have application software built into the site.
• Web page authoring software can create sophisticated Web pages that include images, video, audio, animation, and other effects

Multimedia Program Development

• Multimedia authoring software allows programmers, to combine text, graphics, animation, audio, and video in an interactive presentation.

Program Development

• Program development consists of a series of steps programmers use to build computer programs.

Step 1 - Analyze Requirements
To initiate program development, programmer: i) review the requirements ii) meets with the system analyst and users iii) identifies input, processing, and output.

Step 2- Design Solution

• Design solution algorithm
• In structured design, the programmer typically begins with a general design and moves toward a more detailed design.
• Programmers use a hierarchy chart to show program modules graphically.
• With object-oriented (OO) design, the programmer packages the data and the program into a single object.
• The sequence control structure shows one or more actions following each other in order.
• The selection control structures tells the program which action to take, based on a certain condition.
• The repetition control structure enables a program to perform one or more actions repeatedly as long as a certain condition is met.
• A program flowchart graphically shows the logic in a solution algorithm.
• Flowcharting software makes it easy to modify and update flowcharts.
• UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development.

Step 3 - Validate Design

• Check for logic errors using test data.

Step 4 - Implement Design

• Implementation of the design includes using a program development tool that assists the programmer by: i) generating or providing some or all code ii) Writing the code that translates the design into a computer program iii) Creating the user interface.
• Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.

Step 5 - Test Solution

The goal of program testing is to ensure the program runs correctly and is error free.

• Errors include syntax errors and logic errors
• Debugging the program involves removing the bugs
• A beta is a program that has most or all of its features and functionality implemented.

Step 6 - Document Solution

• In documenting the solution, the programmer performs two activities: Review the program code and all the documentation.

Chapter 12 : Exploring Information System Development

What is System Development?
System development is a set of activities used to build an information system. A system is a set of components that interact to achieve a common goal. An information system (IS) is a collection of hardware, software, data, people, and procedures that work together to produce quality information.

• System development should follow three general guidelines: i) Group activities or tasks into phases ii) involve users iii) define standards.
• 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: Project scope, Required activities, Order of activities.
• Feasibility is a measure of how suitable the development of a system will be to the organization. Operational feasibility, Schedule feasibility,  Technical feasibility, Economic feasibility.
• Documentation is the collection and summarization of data and information.
• Users and IT professionals refer to existing documentation when working with and modifying current systems.

Planning Phase

• 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, Prioritize the project requests, Allocate resources, Form a project development team.

Analysis Phase

• Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs.
• An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system.
• Entities are objects in the system that have data.
• A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.
• The project dictionary contains all the documentation and deliverables of a project.
• Structured English is a style of writing that describes the steps in a process.
• The data dictionary stores the data item's name, description, and other details about each data item.
• Object modeling combines the data with the processes that act on that data into a single unit, called an object.
• UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development.
• A use case diagram graphically shows how actors (users) interact with the information system.
• The system proposal assesses the feasibility of each alternative solution.
• The steering committee discusses the system proposal and decides which alternative to pursue.

Design Phase

• The design phase consists of two major activities - Acquire hardware and software, Develop all of the details of the new or modified information system.
• Systems analysts typically develop two types of designs for each input and output.
• A prototype (proof of concept) is a working model of the proposed system. Prototypes have inadequate or missing documentation. 

Implementation Phase

• The purpose of the implementation phase is to construct the new or modified system and then deliver it. Develop programs > Install and test the new system > Train users > Convert to the new system.
• Various tests should be performed on the new system. Unit test - verifies that each individual program or object works by itself. Systems test - verifies that all programs in an application work together properly. Integration test - verifies that an application works with other applications. Acceptance test - checks the new system to ensure that it works with actual data.
• Training involves showing users exactly how they will use the new hardware and software in the system.
• One or more of four conversion strategies can be used to change from the old system to the new system.

Operation, Support, and Security Phase

• The purpose of the operation, support, and security 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.
• A computer security plan should do the following: Identify all information assets of an organization. Identify all security risks that may cause an information asset loss. For each risks, identify the safeguards that exist to detect, prevent, and recover from a loss.

Chapter 11 : Manage Computing Securely, Safely and Ethically

Computer Security Risks

• A computer security risk is any event or action that could cause a loss of or damage to computer hardware, software, data, information, or processing capability.
• A cybercrime is an online or Internet-based illegal act.

Internet and Network Attacks

• An online security service is a Web site that evaluates your computer to check for Internet and e-mail vulnerabilities.
• Computer virus - Affects a computer negatively by altering the way the computer works.
• Worm - Copies itself repeatedly, using up resources and possibly shutting down the computer or network.
• Trojan Horse - A malicious program that hides within or looks like a legitimate program.
• Rootkit - Program that hides in a computer and allows someone from a remote location to take full control.
• An infected computer has one or more of the following symptoms: Files become corrupted, Available memory is less than expected, System properties change, Operating system shuts down unexpectedly.
• A botnet is a group of compromised computers connected to a network. A compromised computer is known as a zombie.
• A back door is a program or set of instructions in a program that allow users to bypass security controls.
• Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate.
• A firewall is hardware and/or software that protects a network's resources from intrusion.

Unauthorized Access and Use
Unauthorized access is the use of a computer or network without permission.
Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.

• Access controls define who can access a computer, when they can access it, and what actions they can take. i) User name ii) Password iii) CAPTCHA
• Digital forensics is the discovery, collection, and analysis of evidence found on computers and networks
• Many areas use digital forensics : Law enforcement, Criminal prosecutors, Military intelligence, Insurance agencies.

Hardware Theft and Vandalism
Hardware theft is the act of stealing computer equipment.
Hardware vandalism is the act of defacing or destroying computer equipment.

• To help reduce the chances of theft, companies and schools use a variety of security measures : i) Alarm systems, ii) Cables to lock equipment, iii) Real time location system, iv) Physical access controls.

Software Theft

• Software theft occurs when someone : Steals software media, Illegally copies a program, Intentionally erases programs, Illegally registers and/or activates a program.
• A single-user license agreement typically contains the following conditions: i) Permitted to - Install the software on one computer. Make one copy of the software. Remove the software from your computer before giving it away or selling it. 
• Some software requires product activation to function fully.

Information Theft

• Information theft occurs when someone steals personal or confidential information.
• Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.
• A digital signature is an encrypted code that a person, Web site, or organization attaches to an electronic message to verify the identity of the sender.

System Failure

• A system failure is the prolonged malfunction of a computer.
• A variety of factors can lead to system failure, including : Aging hardware, Natural disasters, Electrical power problems.
• Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptable power supplies (UPS). 

Backing Up - The Ultimate Safeguard

• A backup is a duplicate of a file, program, or disk that can be used if the original is lost, damaged, or destroyed. To back up a file means to make a copy of it
• Offsite backups are stored in a location separate from the computer site.

Wireless Security
In additional to using firewalls, some safeguards improve security of wireless networks: A wireless access point should not broadcast an SSID, Change the default SSID, Use WPA or WPA2 security standards.

Ethics and Society

• Computer ethics are the moral guidelines that govern the use of computers and information systems.
• Information accuracy is a concern.

Intellectual property rights are the rights to which creators are entitled for their work. An IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical.

• Green computing involves reducing the electricity and environmental waste while using a computer.
• Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them.
• A cookie is a small text file that a Web server stores on your computer. Reasons for this web sites cookies are : i) Allow for personalization ii) Target advertisements iii) Store users passwords.
• Spam is an unsolicited e-mail message or newsgroup posting.
• E-mail filtering blocks e-mail messages from designated sources.
• Anti-spam programs attempt to remove spam before it reaches your inbox.
• Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantages of trust and naivety.
• Employee monitoring involves the use of computers to observe, record, and review an employee's use of a computer.
• Content filtering is the process of restricting access to certain material on the Web.
• Web filtering software restricts access to specified Web sites.

Chapter 10 : Managing a Database

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 such as Text, Numbers, Images, Audio, Video
• Information - Processed data, Documents, Audio, Images, Video
• Database software, often called a database management system (DBMS), allows users to: Create a computerized database. Sort and retrieve data.
• Data integrity identifies the quality of the data.
• Garbage in, garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input.
• Valuable information should have the following characteristics : Accurate, Verifiable, Timely, Organized, Useful, Accessible, Cost-effective.

The Hierarchy of Data

• A character is one byte - Numbers, letters, space, punctuation marks, or other symbols.
• A field is a combination of one or more related characters. i) Field name ii) Field size iii) Data type.
• Common data types include : Text, Numeric, Date, Memo, Object, AutoNumber, Currency.
• A record is a group of related fields - A primary key uniquely identifies each record.
• A data file is a collection of related records.

Maintaining Data

• File maintenance refers to the procedures that keep data current ; i) Adding records ii) Modifying records iii) Deleting records.
• Users add new records to a file when they obtain new data.
• Users modify a record to correct inaccurate data or update old data.
• Validation compares data with a set of rules or values to find out if the data is correct.

File Processing Versus Databases

• File processing system : i) used for many years. ii) have data redundancy. iii) isolate data
• Database approach : i) reduce data redundancy ii) share data iii) allows easier access.

Database Management Systems

• A data dictionary contains data about each file in the database each field in those files.
• A DBMS provides tools allow users to retrieve and maintain data in the database - Query language, Query by example, Form, Report generator.
• A query language consists of simple, English-like statements that allow users to specify the data to display, print, or store.
• Query by example (QBE) provides a GUI to assist users with retrieving data.
• A form is a window on the screen that provides areas for entering or modifying data in a database.
• A report generator allows users to design a report on the screen, retrieve data into the report design, and then display or print the report.
• A DBMS provides a variety of techniques to restore the database to a usable form in case it is damaged or destroyed such as Backup, Log, Recovery utility, Continuous backup.

Relational, Object-Oriented, and Multidimensional Databases

• A data model consists of rules and standards that define how the database organizes data.
• A relational database stores data in tables that consists of rows and columns. Each row has a primary key. Each column has a unique name.
• A relationship is a link within the data.
• An object-oriented database (OODB) stores data in objects.
• Examples of applications appropriate for an object-oriented database include : multimedia database, Groupware database, Hypertext database.
• A multidimensional database can store data in more than two dimensions of data
• A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.

Web Database

• Databases on the Web allow you to: Check semester grades, Search for a job, Buy or sell stocks, Shop for products or services, Make airline reservations, Register for college classes.

Database Administration

• It is important to have a carefully designed database.
• Employees should learn how to use the data in the database effectively. Interact with database. Identify new data for the database. Maintain the database.

Chapter 9 : Networks and Communications

Communications

• Communications describes a process in which two or more computers or devices transfer data, instructions, and information. Sending device, Communications channel, Receiving device.

Uses of Computer Commuications

• Users can send and receive wireless messages using wireless messaging services. Text messaging allows users to send message thru phone or other mobile devices. Picture messaging allows users to send pictures and sound files. Video messaging allows users to send short video clips.
• Wireless Internet access points allow people to connect wirelessly to the Internet from home, work, school, and in many public locations.
• A cyber cafe is a coffeehouse, restaurant, or other location that provides personal computers with Internet access to its customers.
• A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the GPS receiver's geographic location.
• Groupware : helps groups of people work together on projects and share information over a network. Major feature is group scheduling.
• Voice mail : allows someone  to leave a voice message for one or more people. A voice mailbox is a storage location on a hard disk in the voice mail system.
• Many programs provide a means to collaborate, or work online, with other users connected to a server.
• A mash-up is a Web application that combines services from two or more sources.

Networks

• A network is a collection of computers and devices connected together via communications devices and transmission media. Advantages of a network include : Sharing hardware and software, Transferring funds, and Sharing data and information.
• A local area network (LAN) is a network that connects computers and devices in a limited geographical area
• A wireless LAN (WLAN) is a LAN that uses no physical wires.
• A wide are network (WAN) is a network that covers a large geographical area.
• A network topology refers to the layout of the computers and devices in a communications network.

An intranet is an internal network that uses Internet technologies.
An extranet allows customer or suppliers to access part of its intranet.

Network Communications Standards
Ethernet is a network standard that specifies no computer controls when data can be transmitted. The token ring standard specifies that computers and devices on the network share or pass a specual signal (token). TCIP/IP is a network standard that defines how messages are routed from one end of a network to another.

• Bluetooth defines how two Bluetooth devices use short-range radio waves to transmit data.
• WiMAX (802.16) : Developed by IEEE. Towers can coer a 30-mile radius. Provides wireless broadband Internet access.
• Wireless Application Protocol (WAP) : Specifies how some mobile devices can display the content of Internet services. Uses a client/server network.

Communications Software

• Communications software consists programs that : i) Help users establish a connection to another computer or network. ii) Manage the transmission of data, instructions, and information. iii) Provide an interface for users to communicate with one another.

Communications Over the Telephone Network

• The public switched telephone network (PSTN) is the worldwide telephone system.
• ADSL connections transmit data downstream at a much faster rate than upstream.

Communications Devices

• A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending deice and a receiving device.
• A dial-up modem converts signals between analog and digital.
• A digital modem sends and receives data and information to and from a digital line such as DSL modem and Cable modem.
• A wireless modem uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device.
• A network card enables a computer or device to access a network.
• Wireless network cards often have an antenna.
• A router connects multiple computers or other routers together and transmits data to its correct destination on a network.
• Many are protected by a hardware firewall.

Home Networks

• Home networks provide computers with the following capabilities : Connect to the Internet at the same time, Play multiplayer games, and Connect game consoles to the Internet.
• Types of wired home networks : Ethernet, Powerline cable, Phoneline.

Wireless Transmission Media

• Cellular radio is a form of broadcast radio that its used widely for mobile communications.
• Microwaves are radio waves that provide a high-speed signal transmission.
• A communications satellite is a space station that receives mircowaves signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area.

Chapter 8 : Types of Storage

Storage
Storage holds data, instructions, and information for future use. A storage medium is the physical material on which a computer keeps data, instructions, and information.

• Capacity is the number of  bytes a storage medium can hold.
• A storage device is the computer hardware that records and/or retrieves items to and from storage media. Reading is the process of transferring items from a storage medium into memory. Writing is the process of transferring items from memory to a storage medium.

Hard Disks

• A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information.
• Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.

Flash Memory Storage

• Flash memory chips are a type of solid state media and contain no moving parts.
• A memory card is a removable flash memory device that you insert and remove from a slot in a computer, mobile device, or card reader.
• USB flash drives plug into a USB port on a computer or mobile device.

Cloud Storage

• Cloud storage is an Internet service that provides storage to computer users for variety of reasons such as : Access file from any computer, Store large files instantaneously, Allow others to access their files.

Optical Discs

• An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.
• Typically store software, data, digital photos, movies, and music.

Other types of storage

• Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information.
• A tape drive reads and writes data and information on a tape.
• A magnetic stripe card contains a magnetic stripe that stores information.
• A smart card stores data on a  thin microprocessor embedded in the card.
• Microfilm and microfiche store microscopic images of documents on a roll or sheet film.