“Happiness” is a dumb metric within a work context.

Success is measured in outcome not output and blithely sailing past a deadline while deliriously happy is not my idea of a good thing.

Also, satisfaction at work, while important, is not measurable in the emotion scale I associate with happiness.

Confidence, the feeling of achievement, satisfaction in a job well done and appreciation of said work are all contributing factors to a stable emotional base.

Happiness though, is a different category and dependent on a different social context. It relies in part on the experiences within the work context but cannot not be quantified in isolation.