2+2=4; Four Eyes Principle

What is 2 + 2 = 4; four eyes principle?

Four eyes principle, work on base of two man rule over system for correctness, maker and checker, in Information Technologies IT word, coder and reviewer.

What is advantage of four eyes principle?

Very simple, we have coder and reviewer in place, as coder write code for app/system in respective language then review will do the review and so on. This process will happen till end of system delivery.

e.g. 

Coder, write the code in java:

 public class ClsMain

 {

 Public static void main(String arg[]){

 System.out.println(“Hello

 }

 }

Reviewer, review the code and suggest for correctness:

 /*****************************************************/

 /* ClsMain.java, for printing the “Hello, http://tutorialbyexample.com”  

 /* Author : Tutorial by Example

 /* Date : 06-Jul-2015

 /*****************************************************/

 public class ClsMain{

     /* Main method with args as string parameters */

     public static void main(String[] args) {

         System.out.println("Hello, http://tutorialbyexample.com");

    }

 }

Note: this principle is already implemented in so many product base organizations.

References:

1. http://www.unido.org