Chapter 6: Networks

In these post I will highlight the most important point in every section of chapter six


6.1 What Is a Computer Network?



A computer network is a system that connects computers and other devices via communications media so that data and information can be transmitted among them.


*Size of Computer Networks:-

• Home computer network

• National computer network

• Global computer network

  *Local Area Networks:-

A local area network connects two or more devices in a limited geographical region so that every device on the network can communicate with every other device.

6.2 Network Fundamentals


*Analog and Digital Signals:-

• Communications Media and Channels:

•      Twisted-pair wire

•      Coaxial cable

•       Fiber optics

• Transmission Technologies:

•    Digital Subscriber Line: a high-speed, digital data transmission technology using existing analog telephone lines.

•    Asynchronous Transfer Mode: data transmission technology that uses packet switching and allows for almost unlimited bandwidth on demand.

•    Synchronous Optical Network: an interface standard for transporting digital signals over fiber optic lines that allows users to integrate transmissions from multiple vendors.

•    T-Carrier System: digital transmission system that defines circuits that operate at different rates, all of which are multiples of the basic 64 Kbps user to transport a single voice call.

*Network Protocols:

   A protocol is the set of rules and procedures governing transmission across a network.
   Ethernet is a common LAN protocol.
 
  Transmission Control Protocol/Internet Protocol (TCP/IP) is a file transfer protocol that can send large files of information across sometimes unreliable networks with assurance that the data will arrive uncorrupted


Types of Network Processing:

• Client/server computing

• Peer-to-peer processing

6.3 The Internet and the World Wide Web



*Addresses on the Internet:

  Domain names consist of multiple parts, separated by dots, which are red from right to left.

  Top-level domain: the rightmost part of an Internet name; common top-level domains are .com, .edu, .gov

  Name of the company: the next section of the Internet name

  Name of the specific computer: the next section of the Internet name

*The World Wide Web:


 World Wide Web: A system of universally accepted standards for storing, retrieving, formatting, and displaying information via a client/server architecture.

 Home page: a text and graphical screen display that usually welcomes the user and explains the organization that has established the page.

Uniform resource locator: the set of letters that points to the address of a specific resource on the Web.

6.4 Network Applications



 *Discovery

Discovery allows users to browse and search data sources, in all topic areas, on the Web.

Search engines are computer programs that search for specific information by key words and report the results.

Metasearch engines search several engines at once and integrate the findings of the various search engines to answer queries posted by users.


The largest search engines are:

• Google
• Yahoo
• Bing
• Baidu

*Portals

Portal is a Web-based, personalized gateway to information and knowledge that provides relevant information from different IT systems and the Internet using advanced search and indexing techniques.

Commercial (public) portals offer content for diverse communities and are most popular portals on the Internet.

Affinity portals support communities such as a hobby group or a political party.

Mobile portals are accessible from mobile devices.

Corporate portals offer a personalized single point of access through Web browser Industry wide portals for entire industries.

*Communication

Electronic mail (e-mail) is the largest-volume application running on the Internet.

Web-based call centers (customer call center) are services that provide effective personalize customer contact as an important part of Web-based customer support.

Electronic chat room is a virtual meeting place where groups of regulars come to “gab”.

*Voice Communication

Internet telephony (VoIP) (voice-over IP) digitizes your analog voice signals, sections them into packets, and sends them over the Internet.

 Two examples of Internet telephony (VoIP):

•      Skype
•      Vonage

  *Collaboration

Collaboration refers to efforts of two or more entities (individuals, teams, groups, or organizations) who work together to accomplish certain tasks.

Work group refers specifically to two or more individuals who act together to perform some task.

Virtual group (team) is when group members are in different locations.

Virtual collaboration is the use of digital technologies that enable organizations or individuals to collaboratively plan, design, develop, manage and research products, services and innovative applications.

Workflow technologies facilitate the movement of information as it flows through the sequence of steps that make up an organization’s work procedures. Includes workflow management and workflow systems.

Groupware refers to software products that support groups of people who share a common task or goal and who collaborate to accomplish it.

Teleconferencing is the use of electronic communication that allows two or more people at different locations to hold a simultaneous conference.

Videoconference is when participants in one location can see participants at other locations and share data, voice, pictures, graphics and animation by electronic means.

Web conferencing is videoconferencing conducted over the Internet.

Real-time collaboration tools support synchronous communication of graphical and text-based information i.e. computer-based whiteboards.

 *Telecommuting

Telecommuting Benefits:

• For Employees:

• Reduced stress, improved family life

• Employment opportunities for single parents and persons with disabilities

• For Employers:

• Increased productivity

• Ability to retain skilled employees

Telecommuting Disadvantages:

• For Employees:

• Feelings of isolation

• No workplace visibility

• Potential for slower promotions

• For Employers:

• Difficulties in supervising work

• Potential information security problems

• Additional training costs

Chapter 5: Managing Knowledge and Data

In these post I will highlight the most important point in every section of chapter five


5.1 Managing Data




Difficulties in managing data:

• Amount of data increasing exponentially

• Data are scattered throughout organizations and collected by many individuals   using various methods and devices.

• Data come from many sources.

• Data security, quality, and integrity are critical.

Data governance: is an approach to managing information across an entire organization.

Master data management: is a process that spans all of an organization’s business processes and applications.

Master data: are a set of core data that span all of an enterprise’s information systems.

5.2 The Database Approach


*Database management system (DBMS) minimizes the following problems:


Data redundancy: The same data are stored in many places.

Data isolation: Applications cannot access data associated with other applications.

Data inconsistency: Various copies of the data do not agree.



*DBMS's maximize the following issues:

Data security: Keeping the organization’s data safe from theft, modification, and/or destruction.

Data integrity: Data must meet constraints (e.g., student grade point averages cannot be negative).

Data independence: Applications and data are independent of one another. Applications and data are not linked to each other, meaning that applications are able to access the same data.

*Data Hierarchy:

A bit is a binary digit, or a “0” or a “1”.

A byte is eight bits and represents a single character (e.g., a letter, number or symbol).

A field is a group of logically related characters (e.g., a word, small group of words, or identification number).

A record is a group of logically related fields (e.g., student in a university database).

A file is a group of logically related records.

A database is a group of logically related files.

*Designing the Database:


Data model: The data model is a diagram that represents the entities in the database and their relationships.

Entity: An entity is a person, place, thing, or event about which information is maintained. A record generally describes an entity.

Attribute: An attribute is a particular characteristic or quality of a particular entity.

Primary key: The primary key is a field that uniquely identifies a record.

Secondary keys: Secondary keys are other field that have some identifying information but typically do not identify the file with complete accuracy.

*Entity-Relationship Modeling:

Database designers plan the database design in a process called entity-relationship (ER) modeling. ER diagrams consist of entities, attributes and relationships.

Entity classes: Entity classes are groups of entities of a certain type.

Instance: An instance of an entity class is the representation of a particular entity.

Identifiers: Entity instances have identifiers, which are attributes that are unique to that entity instance.






5.3 Database Management Systems



Database management system (DBMS): A database management system is a set of programs that provide users with tools to add, delete, access, and analyze data stored in one location



Relational database model: The relational database model is based on the concept of two-dimensional tables:

• Structured Query Language (SQL): Structured query language allows users to perform complicated searches by using relatively simple statements or keywords.

• Query by Example (QBE): Query by example allows users to fill out a grid or template to construct a sample or description of the data he or she wants.

*Normalization:

Normalization is a method for analyzing and reducing a relational database to its most streamlined form for:

• Minimum redundancy

• Maximum data integrity

• Best processing performance

Normalized data occurs when attributes in the table depend only on the primary key.

5.4 Data Warehousing



Data warehouses and Data Marts: A data warehouse is a repository of historical data organized by subject to support decision makers in the organization.


Benefits of Data Warehousing

• End users can access data quickly and easily via Web browsers because they are located in one place.

• End users can conduct extensive analysis with data in ways that may not have been possible before.

• End users have a consolidated view of organizational data.

5.5 Knowledge Management




Knowledge management (KM): Knowledge management is a process that helps organizations manipulates important knowledge that is part of the organization’s memory, usually in an unstructured format.


Knowledge: Knowledge that is contextual, relevant, and actionable.


Intellectual capital (or intellectual assets): Intellectual capital is another term often used for knowledge.



*Type of knowledge:


Explicit knowledge: objective, rational, technical knowledge that has been documented. Examples: policies, procedural guides, reports, products, strategies, goals, core competencies


Tacit knowledge: cumulative store of subjective or experiential learning. Examples: experiences, insights, expertise, know-how, trade secrets, understanding, skill sets, and learning




*Knowledge Management System Cycle:

• Create knowledge

• Capture knowledge

• Refine knowledge

• Store knowledge

• Manage knowledge

• Disseminate knowledge

Chapter 2: Information Systems and the Modern Organization

In these post I will highlight the most important point in every section of chapter two

 2.1 Business Processes

    

•  A business process is a collection of related activities that produce a product or a service of value to the organization, its business partners, and/or its customers.

•   A cross-functional business process is one in which no single functional area is responsible for its execution.   

2.2 Business Process Reengineering and Business Process Management

•      Business process reengineering is a radical redesign of a business process that improves its efficiency and effectiveness, often by beginning with a “clean sheet.”

•      Business process management is a management technique that includes methods and tools to support the design, analysis, implementation, management, and optimization of business processes.

2.3 Business Pressures, Organizational Responses, and IT Support

Business Pressure - The business environment is the combination of social, legal, economic, physical, and political factors that affect business activities. Significant changes in any of these factors are likely to create business pressure on the organization.

The three types of business pressures faced are:

•        Market

o   The Global Economy and Strong Competition

o   The Changing Nature of the Workforce

o   Powerful Customers

•       Technology

o   Technological Innovation and Obsolescence

o   Information Overload

•   Societal pressures

o   Social Responsibility

o   Government Regulation and Deregulation

o   Protection Against Terrorist Attacks

o   Ethical Issues

2.4 Competitive Advantage and  Strategic Information Systems

• Competitive Advantage: An advantage over competitors in some measure such as cost, quality, or speed, leads to control of a market and to larger- than average profits.

• Strategic Information Systems (SIS) provides a competitive advantage by helping an organization to implement its strategic goals and to increase its performance and productivity.

*Porter’s Competitive Forces Model

• Threat of entry of new competitors is high when it is easy to enter a market and low when significant barriers to entry exist. 

•   A barrier to entry is a product or service feature that customers expect from organizations in a certain industry. 

• For most organizations, the Internet increases the threat that new competitors will enter a market.

•  The bargaining power of suppliers is high when buyers have few choices and low when buyers have many choices.

•   Internet impact is mixed.  Buyers can find alternative suppliers and compare prices more easily, reducing power of suppliers.

•  On the other hand, as companies use the Internet to integrate their supply chains, suppliers can lock in customers.

•  The bargaining power of buyers is high when buyers have many choices and low when buyers have few choices.

•   Internet increases buyers’ access to information, increasing buyer power.

•  Internet reduces switching costs, which are the costs, in money and time, to buy elsewhere.  This also increases buyer power.

• The threat of substitute products or services is high when there are many substitutes for an organization’s products or services and low where there are few substitutes.

• Information-based industries are in the greatest danger from this threat (e.g., music, books, software).  The Internet can convey digital information quickly and efficiently.

• The rivalry among firms in an industry is high when there is fierce competition and low when there is not.

*Porter’s Value Chain Model

This model identifies specific activities where organizations can use competitive strategies for greatest impact.

·        

•  Primary activities are those business activities that relate to the production and distribution of the firm’s products and services, thus creating value for which customers are willing to pay.  Primary activities include inbound logistics, operations, outbound logistics, marketing and sales, and customer service.

•   Support activities do not add value directly to a firm’s products and services, but support the primary activities.  Support activities include accounting, finance, management, human resources management, product and technology development (R&D), and procurement.

*Strategies for Competitive Advantage

• Cost Leadership: Produce products and/or services at the lowest cost in the industry.

• Differentiation: Offer different products, services or product features.

• Innovation: Introduce new products and services, add new features to existing products and services or develop new ways to produce them.

• Operational Effectiveness: Improve the manner in which internal business processes are executed so that a firm performs similar activities better than its rivals.

• Customer-orientation: Concentrate on making customers happy.