Hi
   when Screen shots are ready we can write 
                   RTM
   Based on RTM we can write the Test Cases 
                   or
   we can design the Test Cases.
  


sun_ramprasad@yahoo.com

a)	When the requirements documents already prepared 
the start to with respect to test design 
b)	That is very importance to testers
c)	 Based on test design here start the write the test 
case and other testing preparation
d)	So very importance of that test designs


My name is k.chandra sekhar,
My phone no are 9246540049 65880049 ,Hyderabad.
My mail id is ndra_143@yahoo.co.in 
I am take the class for projects if you interst contact
If any body want full explain send the mail

When we get the requriment we can start designing the 
testcase

Test Design. 

It is A document specifying the test condition(coverage 
item) for a test item. 

It is also known as Test Design Specification.