Quite often, we need help from other departments. Whenever I need to do so, I always give them enough time to respond, or enough understanding if they can't respond in time.
However, a colleague of mine from another department (who has once asked for my help) didn't come to me beforehand but went directly to my boss instead and said, that's a very easy job, will take him an hour at most (writing a tcl program). However, my estimate is that writing it alone will take 3 or 4 hours, and making sure it works as expected will take another hour or two, and indeed it took me almost a day to do a good job. In other words, he deliberately downplayed the effort to writing that tcl program, deliberately making it not a big deal, and my manager believes him more than me.
This is really bothersome. If I write a bad program in an hour, he will surely come back to my boss complaining that I've done a bad job. If I do a good job, then my boss will say, "What took you so long?"
"I would say if he knows it is a 1 hour task then he should do it himself." Yeah, definitely, totally agree. If I have a task that takes me two or even three hours to do myself, I wouldn't go through the hassle of going through another department's manager, and asking people from another department to do it for me. The only reason he did it, was that he and my manager were quite close, and I was new in the company (and was new to tcl as well). I bet the whole conversation between him and my manager was just, "I need xxx to help me writing a tcl program, a very easy one, will take him an hour at most", "Yeah, sure, I'll ask him". When you are new, you have to do whatever you are told. I don't mind doing it, but such attitude of soliciting help but showing no sign of consideration and appreciation made me very uncomfortable.
I.e., either case, I think I'm losing. How would you deal with such colleagues that want to borrow your time, but downplay your effort? Your answer can help me better prepared next time when I bump into such person again.