Nassi-Shneiderman Diagram (NSD)

Nassi-Shneiderman diagram (NSD) is a graphical representation (structogram) for structured programs.

The Nassi-Shneiderman diagram offers elements for all the basic blocks in structured programming:

  • Function - represents a program, function, or procedure. It includes other blocks.
  • Process - represents the simplest unit, a single step in an algorithm. This element cannot contain any other nested elements.
  • Condition (Branch) - represents a block that offers multiple conditional execution blocks. The basic form of Condition element offers two parts - true (condition is fulfilled) and false (condition is not fulfilled, else branch). This condition block can represent the if-then-else condition. The element can also include more than two parts - value1, value2 ... valueN, and otherwise. In this configuration, the Condition element may be used for select/switch statements with multiple choices. The conditional branches are displayed side by side horizontally.
  • Loop - represents a block that is executed repeatedly while the condition is fulfilled. The condition test may be done before or after the execution block. The Loop element can include other nested elements that represent the loop body.
  • Concurrent - the block represents a parallel execution. The parallelly executed blocks are placed side by side horizontally.

NSD Chart Symbols

The following picture shows the overview of symbols that can be used to build an NSD chart:

Nassi Shneiderman Diagram (NSD) Overview
Nassi Shneiderman Diagram (NSD) Overview

NS Diagram Maker

Software Ideas Modeler provides an editor for NS diagrams creation. You can download it for free with the button below.

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