Quality
While the main reason for using a robot is to save labor the biggest impact a robot has can be on quality.
Applications where quality will be improved are:
gluing,
spraying (glue or paint),
trimming and de-burring,
testing and gauging.
assembly
laboratory routines
Sometimes a human operator can do better than the robot in terms of quality or speed but the robot will do the task consistently.
For example testing and gauging is often open to human interpretation. Different operators will get differing results. The same has been found to apply in laboratory routines, especially pharmaceutical research where hundreds of sample must be tested with sensitive instruments. Results obtained vary with the operator speed, handling, etc. Applications where the objective has been to save the costs of PhD scientists filling test tubes often yielded more repeatable and accurate results.