water fall model in failure model this modelcontinue 
process for develpment and testing process inbetween 
problem available  is not possible to rectfied to continue 
the process again star the proces initial start the 
processthis process continiusily going on thats y thiss 
model didnt use cocerns
velu CYBERTECHNOLOGIES
9942343411

its a sequential model.in which testing was done at the 
last stage.so problems are there while handling the testing 
in the last.its expensive too

Water fall model is one of the software development life 
cycle model. that is used in any organization from the 
beginning to the end the flow of these model looks like 
water fall model that s why it is called  has a waterfall 
model.