Explain system designing tools.

q)Explain system designing tools.
ans:-

Systems Design: In this phase we start design of proposed new system.It describes desired features and operations in detail, including screen layouts, business rules, process diagrams, pseudo code and other documentation. We can use two designing methods namely logical (what is required for IS) and physical (how to achieve requirements). At first we design logical and then it is converted into physical design. A prototype should be developed during the logical design phase if possible. The detailed design phase modifies the logical design and produces a final detailed design, which includes technology choices, specifies a system architecture, meets all system goals for performance, and still has all of the application functionality and behavior specified in the logical design.

          This design can carry following activities:

• Defining precisely the required system output
• Determining the data requirement for producing the output
• Determining the medium and format of files and databases
• Devising processing methods and use of software to produce output

We can use several tools while designing. They are: Algorithm, Flowchart, Pseudo code, etc. Let’s see in detail about some of these all designing tools.

I) Algorithm:

An algorithm is an effective method or a tool for solving a problem using a finite sequence of well organized instructions. Algorithms are used for calculation, data processing, and many other fields.

                                  Each algorithm is a list of well-defined instructions for completing a task. Starting from an initial state, the instructions describe a computation that proceeds through a well-defined series of successive states, eventually terminating in a final ending state. For example,

-->start

-->read a no. x

-->read a no. y

→ let sum=x+y

-->display sum

-->stop

                           II) Flowchart:- It is a common type of diagram or picture, that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. Or simply we can say a graphical representation of algorithm. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields. Some symbols used in flowcharts are Oval, parallelogram, rectangle, flowline, annotation etc. different symbols have different meanings. For example,

           

                                    

Pseudo Code:

Pseudo-Code is simply a numbered list of instructions to perform some task. Here Pseudo means fake. So it is a fake code which we use to convert algorithms. In this we use many English words or verbs like START/BEGIN, DO, WHILE, HALT,STOP,INITIALIZE etc, Any case can be used. Writing Pseudocode is just like reading a story. So it’s easy to write and understand. For example,

BEGIN

GET GRADE

IF student's grade is greater than or equal to 80

      Print "passed in distinction"

ELSE

      Print "other division"

HALT