IT Concept and Management

PTI Pertemuan 3

Today’s Lessons

Information Systems Concepts Definition

Information System Infrastructure and Architecture Information Infrastructure IT Infrastructure Mainframe Environment PC Environment Distributed Computing Peer-to-peer (P2P) architecture

Web-Based Systems Web Based Functionalities Internet-Intranet-Extranet E-Commerce Systems

New Computing Environments Grid Computing Web Service

Information Systems

Concepts Definition

Information System Concept

Information Systems (IS) is a professional and academic discipline concerned with the strategic, managerial and operational activities involved in the gathering, processing, storing, distributing and use of information, and its associated technologies, in society and organizations.

As an area of study, IS bridges the multidisciplinary business field and the interdisciplinary computer science field that is evolving toward a new scientific discipline.

An information systems discipline therefore is supported by the theoretical foundations of information and computations such that undergraduate students have unique opportunities to explore the academics of various business models as well as related algorithmic processes within a computer science discipline.

Typically, information systems or the more common legacy information systems include people, procedures, data, software, and hardware (by degree) that are used to gather and analyze digital information.

Information System Definition

Silver et al. defined Information Systems as follows:

Information systems are implemented within an organization for the purpose of improving the effectiveness and efficiency of that organization. Capabilities of the information system and characteristics of the organization, its work systems, its people, and its development and implementation methodologies together determine the extent to which that purpose is achieved

Information System Infrastructure and Architecture Information Infrastructure IT Infrastructure Mainframe Environment PC Environment Distributed Computing Peer-to-peer (P2P) architecture

Information Infrastructure

An information infrastructure is defined by (Hanseth, 2002) as "a shared, evolving, open, standardized, and

heterogeneous installed base“

and by (Pironti, 2006) as all of the people, processes, procedures, tools, facilities, and technology which supports the creation, use, transport, storage, and destruction of information.

IT Infrastructure

In information technology and on the Internet, infrastructure is the physical hardware used to interconnect computers and users.

Infrastructure includes the transmission media, including telephone lines, cable television lines, and satellites and antennas, and also the routers, aggregators, repeaters, and other devices that control transmission paths.

Infrastructure also includes the software used to send, receive, and manage the signals that are transmitted.

In some usages, infrastructure refers to interconnecting hardware and software and not to computers and other devices that are interconnected.

However, to some information technology users, infrastructure is viewed as everything that supports the flow and processing of information.

Infrastructure companies play a significant part in evolving the Internet, both in terms of where the interrconnections are placed and made accessible and in terms of how much information can be carried how quickly.

Mainframe Environments

Mainframes are powerful computers used mainly by large organizations for critical applications.

DefinitionThe mainframe environment is the most mature IT area and as such boundaries as well as metrics are clearly defined and known.Unlike the other IT areas, the mainframe area is also (typically) an environment where Vendors own all mainframe-related hardware and software.

TrendThe major trend is moving off the mainframe to midrange platforms. However, as history has shown, the move takes much longer than anticipated.

PC Environment

A personal computer (PC) is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end user with no intervening computer operator.

This is in contrast to the batch processing or time-sharing models which allowed large expensive mainframe systems to be used by many people, usually at the same time, or large data processing systems which required a full-time staff to operate efficiently.

A personal computer may be a desktop computer, a laptop, a tablet PC, or a handheld PC (also called a palmtop). The most common microprocessors in personal computers are x86-compatible CPUs. Software applications for personal computers include word processing, spreadsheets, databases, Web browsers and e-mail clients, games, and myriad personal productivity and special-purpose software applications. Modern personal computers often have connections to the Internet, allowing access to the World Wide Web and a wide range of other resources.

Distributed Computing

Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal. A computer program that runs in a distributed system is called a distributed program, and distributed programming is the process of writing such programs.

Distributed computing also refers to the use of distributed systems to solve computational problems. In distributed computing, a problem is divided into many tasks, each of which is solved by one computer.

Peer-to-peer (P2P) architecture

Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or work loads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes.

Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model where only servers supply, and clients consume.

Web-Based Systems

Web Based Functionalities Internet-Intranet-Extranet E-Commerce Systems

Web Based Functionalities

A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is hosted in a browser-controlled environment (e.g. a Java applet), or coded in a browser-supported language (such as JavaScript, combined with a browser-rendered markup language like HTML) and reliant on a common web browser to render the application executable.

Web applications are popular due to the ubiquity of web browsers, and the convenience of using a web browser as a client, sometimes called a thin client. The ability to update and maintain web applications without distributing and installing software on potentially thousands of client computers is a key reason for their popularity, as is the inherent support for cross-platform compatibility. Common web applications include webmail, online retail sales, online auctions, wikis and many other functions.

Internet-Intranet-Extranet

InternetThis is the world-wide network of computers accessible to anyone who knows their Internet Protocol (IP) address - the IP address is a unique set of numbers (such as 209.33.27.100) that defines the computer's location. Most will have accessed a computer using a name such as http://www.hcidata.com. Before this named computer can be accessed, the name needs to be resolved (translated) into an IP address. To do this your browser (for example Netscape or Internet Explorer) will access a Domain Name Server (DNS) computer to lookup the name and return an IP address - or issue an error message to indicate that the name was not found.Once your browser has the IP address it can access the remote computer. The actual server (the computer that serves up the web pages) does not reside behind a firewall - if it did, it would be an Extranet.

IntranetThis is a network that is not available to the world outside of the Intranet. If the Intranet network is connected to the Internet, the Intranet will reside behind a firewall and, if it allows access from the Internet, will be an Extranet. The firewall helps to control access between the Intranet and Internet to permit access to the Intranet only to people who are members of the same company or organisation. In its simplest form, an Intranet can be set up on a networked PC without any PC on the network having access via the Intranet network to the Internet. For example, consider an office with a few PCs and a few printers all networked together. The network would not be connected to the outside world. On one of the drives of one of the PCs there would be a directory of web pages that comprise the Intranet. Other PCs on the network could access this Intranet by pointing their browser (Netscape or Internet Explorer) to this directory - for example U:\inet\index.htm. From then onwards they would navigate around the Intranet in the same way as they would get around the Internet.

ExtranetAn Extranet is actually an Intranet that is partially accessible to authorised outsiders. The actual server (the computer that serves up the web pages) will reside behind a firewall. The firewall helps to control access between the Intranet and Internet permitting access to the Intranet only to people who are suitably authorised. The level of access can be set to different levels for individuals or groups of outside users. The access can be based on a username and password or an IP address (a unique set of numbers such as 209.33.27.100 that defines the computer that the user is on).

E-Commerce Systems

Electronic commerce, commonly known as e-commerce or eCommerce, or e-business consists of the buying and selling of products or services over electronic systems such as the Internet and other computer networks. The amount of trade conducted electronically has grown extraordinarily with widespread Internet usage. The use of commerce is conducted in this way, spurring and drawing on innovations in electronic funds transfer, supply chain management, Internet marketing, online transaction processing, electronic data interchange (EDI), inventory management systems, and automated data collection systems. Modern electronic commerce typically uses the World Wide Web at least at some point in the transaction's lifecycle, although it can encompass a wider range of technologies such as e-mail as well.

A large percentage of electronic commerce is conducted entirely electronically for virtual items such as access to premium content on a website, but most electronic commerce involves the transportation of physical items in some way. Online retailers are sometimes known as e-tailers and online retail is sometimes known as e-tail. Almost all big retailers have electronic commerce presence on the World Wide Web.

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