System analysis and design

System analysis and design is the first chapter of Information Systems subject. In this chaper we are basically discuss about the process of building an information system. First of all we need to understand the meaning of information and system. These are two different words having different meanings.

Information are called as a collection of data that is useful to humans to make decisions. Decision making is an important part of our day to day life. You can find it out yourself!!! Think about your daily routine, how many decisions you take in a day. You make a decision when you need to eat something (lunch as an example) depends on information sends to your mind by your body. That information are the feelings of hungry, thirty, etc. Depends on the weight of these information, you decide when and what you want to eat.

System in other hand is a collection of small functioning units that work together towards achieving a common goal(s). A single functioning unit can not consider as an system. As an example get your pen. The clip of the pen is not an system alone. It does not do any productive work or it doesn't has a goal. But when we consider the pen as a whole, it is a system. The objective of the system is write some thing in a paper. There are many functional units working together to achieve this goal. Pen clip, ink, ink tube, head, ball point, body tube, etc. All these units together create the system called Pen.

So, what is an Information System? We know that information is a collection of data in its simplest explanation. But information alone is useless, we need peoples to get use of information. People need a way to get and use information. That means we need a process of obtaining information and get use from it, as an example reading a book or report. So here the process is 'reading' a book. To read we need a book, and this is called as the interface. Interface is the medium we use to obtain information.

Above we talked about 4 units, information, people, process and interface. So, these are the functional units of an information system. Together all these units we called it as an information system. In an information system we use data to process information, so we used the word data instead of information in an information system.

"Information system is a collection of data, people, process and interface that work together to achieve goals of making decision in a business organization to support and improve data to day works"