Dear PM Advisor, I'm a Team Member on a couple of projects, plus I have a regular boss. That means I have three bosses! Sometimes they tell me to do opposite things. What should I do?"
Whipsawed in New Mexico.
Even though this column is all about Project Management, I'm going to tell you to listen to your Functional Manager (FM), not your Project Manager (PM) whenever there is a conflict. First of all, the FM is the person who reviews you at the end of the year so think of her as the one who signs your paycheck. Secondly, the FM is the person with whom you will have the lasting relationship. She is responsible for developing your skills, mentoring you through difficult stretches and grooming you to take her job.
The PM, on the other hand, is a blood-sucking leech. All he wants to do is take your knowledge and skills and squeeze them out of you for the life of the project, then throw away your dried up husk when he's done. He has no loyalty to you and wants no long-lasting relationship. If you are really good, he might ask for you again on his next project but chances are that his next project doesn't need anyone with your skills.
So when there is a conflict, listen to your Functional Manager. Tell the PM that she must resolve the conflict with the FM then duck your head and get back to work.