Systems analysis and design

introduction

usually it use to created another program for example from android kitkat to android lollipop system analysts is use to review the system and will suggest to make a improvement to the new system 

analysts stage

use to review the system 

for example

-review the old system

-agreeing the objective with the customer 

-identify and agreeing customer's requirements

-interpreting the customer requirement

Design stage

use to design the key parts of the recommend system 
-like designing the screen layout 
-selecting the validation rules that needs to be used 
-and designing the strategy plan

Verification

use to prevent errors because who want errors to the new system 
-2 method:
-double entry
the data is entered twice with two people they will compare the two entries and they will identify the difference 
-visual check 
checking errors by comparing the data on the screen with the original document