[pzs]

I agree. If I were you, I would try to understand why they behave as they do. They may be distracted because of reasons outside of work (such as an illness in the family, or a divorce lurking around the corner etc.). Or they may be overwhelmed with the complexity of the task and so they just try to do what they think they can instead of working straight towards the solution. After all, we are all people with ups and downs, and limitations of our own. The follow-up should depend on what you find.