* requires less time
for big projects  automation tols used because, we need to 
check the codes , functionality by just creating one 
script. and we can run that script by different input 
values. so it requires less time.

addition to-Raju Korti's comments:
it is the more efficient way of testing which avoids 
general human errors,
Automated tests can be run in absecnce of tester too.
In case of any changes are made on AUT,with minimum changes 
on the script,the scripts are reusable.

1. Almost all current testing  methods  cannot be 
implemented by hand except by the most dedicated or 
desperate testers. 
2. Automation encourages projects to re-test more 
frequently.
3. Reduce testing costs
4. Reduce time spent in the testing phase
5. Detect errors early and to raise the quality of the 
delivered software. 
6. Achieves the repeatability required for valid test 
results.
7. Improve test coverage

1. minimum reqirement of human resource
2. Accuracy
3. reliable
4. less time consuming-- faster than manual testing.
5. Resuable
6. Programmable.

Higher Production rate increase productivity.
minimum requirement of human resource. Shorter workweeks 
after labor.
Efficient use of material.
Saving of expensive utility.
Improve safety. 
Accuracy. 
Reliable. 
Less time consuming. 
Reusable .
Programmable.