Which test case should be automated?

Following

test case should be automated

• Test case need to be run for every build of the application
  (Sanity Testing)
  
• Test that use multiple data values for the same actions.
  (Data Driven Testing)
  
• Critical Application functionality.
• Business functionality which won’t be change in short time period.
• Performance testing
  (Load & Stress)
  

What is 'item pass/ fail creteria' in test plan?

Item Pass /Fail criteria

This section of the test plan describes the pass/fail criteria for each of the items described in Test items.

Sample Pass/Fail criteria for System testing

• 90% of the test cases must pass
• All test cases dealing with critical functionality must pass
• All medium and high severity defects must be fixed
• Test coverage must be at least 90%