From a stranger to a friend.

Below is transcript of my interaction with Rahul. I met him on my journey to Kharagpur. Rahul was around five feet eight inches tall, in his mid twenties and had a distinctive spark in his eyes. Rahul was a property dealer by profession. His seat berth was adjacent to mine. We got along very well and discussed some recent developments in business models. Rahul aspired to improve his business model by using information technology.

Rahul:  Watching outside window...
Me:      Nice scenery. Where are you going?
Rahul:  Kolkata. You?
Me:      Kharagpur.
Rahul:  Are you a student at IIT?
Me:      Yes (with a smile) I am a first year student of management.
Rahul:   Management is the buzz word now a days. What is it and what all is taught ?
Me:      Management is a multi-purpose organ that manages business and manages managers and manages    workers and work. We are taught vast variety of subjects like human behavior, finance, marketing, operations and information technology.
Rahul:   Very interesting. You are the right person then. I have a established property dealer business. I am looking to use information technology in making my business more efficient.(in an inquisitive manner)
Me:      (smiles) That is innovative thinking. By creating a company you can reach potential customers sitting in different locations. An online application will help you maintain and manage huge amount of customer data. In nutshell an efficient three tier system architecture will save time and resources.
Rahul: System architecture! (with a spark in his eyes)  What is it? What do you mean by a three tier system?
ME: Systems Architecture refers to the architecture of a system, i.e. a model to describe or analyze a system. Information system consists of data system,network and application system.

Rahul: Sorry to interrupt. What is data system and application system?

Me: Data system is a term used to refer to an organized collection of symbols and processes that may be used to operate on such symbols . Any organized collection of symbols and symbol-manipulating operations can be considered a data system.

Application system is a program or group of program designed for end users. These programs interact with computer and performs a desired function. It acts as an interface between man and machine.

Rahul: Please help me understand the basics of system architecture.(with a speculative look)

Me: (with a grin) Sure! There are three types of system architectures:
1. Integrated Systems.
2. Two Tier Client Server Architecture.
3. Three Tier Architecture.
 
 (Took a note book and pen out of my bag). Will explain you with help of a diagram.(Draws the pictorial representation)




In Integrated system model data is stored in database which can be DB2, Oracle or SQL. Applications are stored on individual machines. It has business logic and a graphical unit interface. Local area network connects clients machine to server using internet.

Rahul: I understand.(with excitement).

Me: Lets see a Two tier client server architecture.(Draws the pictorial representation)


Multi-tier architecture is a client server architecture in which the presentation, the application processing, and the data management are logically separate processes.
 
Data is stored in the server and application is stored on individual machines. Internet connects individual machines to servers.

Rahul: (with a feeling of joy) I see. Its an improvement on previous model. Multiple users can access application at a time.

Me: You are absolutely right. Now lets see a Three tier architecture.(Draws the pictorial representation)



In a three tier architecture the business logic is kept centrally. The changes to business logic is done at one location only. The presentation logic though is kept locally.

Rahul: (Raised his hand) Got it data transfer over the network is minimized. This will result in lesser network traffic. What about data protection?

Me: You have a good understanding of system architecture now. For data protection fire walls are installed at local computers and servers. They block spyware, worms and viruses. So what architecture you plan to use for your company?


Rahul: My business is small. I plan to use a Two tier architecture.

Me: Do upgrade to three tier when your business grows.

Rahul: Definitely.(with a feeling of satisfaction).

Kharagpur station was about to come in a few minutes. Rahul thanked and appreciated the informative discussion we had. We exchanged our contact details. By the end of journey I made a good friend.


Thanks
Syed Mohd Kashif