Coadvisor assigning seemingly superfluous tasks Context: I am a fourth-year graduate student in mathematics at a university in the US.

One of my colleagues in applied mathematics has two advisors, one in mathematics and one in chemistry.  He's trying to graduate this semester, and he (understandably) wants to devote the majority of his time to writing his thesis, applying to jobs, etc.

Unfortunately, his chemistry advisor seems to be taking advantage of him.  She is continuously asking that he perform all sorts of calculations for her that have nothing to do with his research.  These calculations are not particularly difficult, they just happen to be beyond the mathematical capability of his advisor.  He suspects that she does not consider them important enough that she would do them herself in the case that she could.

As he still needs her to serve as a reference, he is somewhat limited in how he can handle this situation.  His past attempts to refuse or delay working on these "projects" have usually been met with significant resistance.  Any suggestions for how he might proceed are much appreciated.
These calculations are not particularly difficult


If this is true, make this calculation more efficient by, for instance, writing a program or software macro to handle them. When the supervisor asks again, give a due date that is longer than the time he actually needs to do that task. For instance, it takes 1 hour, and after automation it'd take 15 minutes. Tell her 1.5 to 2.0 hours. The earlier stage they are in, the more he can over-estimate the required time to get some breathing room for other tasks pertinent to his study.

He can also consider teaching other people of her lab or team to do the calculation. Make a brief instruction presentation and teach all of them to do it. She may be less likely to call on him again.

The way I dealt with mine may not be the ideal for him: I usually just do the tasks even it may mean some of my research time is reduced. For instance, I spent time writing proposal, making and checking others' presentations and abstracts, training graduate students, etc. just to help my supervisor. For i) if my supervisor is not stressed, our lives are easier, and ii) after looking at my supervisor's overall workload, I just couldn't help but wanted to help. I wanted to aspire to be a graduate student who can take care of own's stuff and with some leftover effort to help. And till now I am still glad that I did.