As a product manager it is tempting to blame failures on the action - or inaction - of others. This is dangerous because it allows one to avoid responsibility for the commtiments they make.
To be a great product manager you have to be a good leader. That means holding yourself accountable. The best definition of accountability I've seen describes accountability as "a personal choice to rise above one’s circumstances and demonstrate the ownership necessary for achieving desired results (Connors, Smith and Hickman, 'The Oz Principle')."
When I worked on the Yahoo! home page a colleague approached me with an idea that would generate significant new revenue. So the two of us sat down to check his math and figure out how to implement it.
It turned out that he was right, but that to implement his idea we'd need to rely on a dysfunctional team in a distant office. As a result, completing the project would require both of us to spend a lot of time doing other peoples' jobs.
So we started the project and began to muddle through. Soon enough, the predicted problems arose and began to slow our progress. Frustrated, I took the issue to my boss and asked for his advice. I described the problem to him and he gave me some detailed guidance. Then, we wrapped up the conversation something like this:
"Will this make money for Yahoo!?"
"Is it good for the user?"
"Do you still want to do this?"
"Yes, but it will be a huge pain in the ass to implement."
"Then don't be a victim. If you really want to do this, you can - and I'll give you all the help you need. It's up to you."
And so I had my revelation.
This project would require me to get my hands very dirty - but the business benefit was huge, and if the project succeeded I would get a lot of the credit. So I decided to commit and push it through.
It turns out that the problems weren't nearly as big as I originally thought. After a week or two of messy work - which consisted mostly of managing people who didn't work for me - we got things on track and launched the feature. And it actually performed as expected, and drove a significant amount of new revenue into our business.
Too many people fall victims to their dependencies. Victims blame others for their failures rather than taking accountablity for things that happen and trying to correct for them. Leaders take accountability for what they commit to do.
That said, smart leaders are very careful what they commit to. You can only take on a few of these "special missions" at once and so you need to save them for the most important things. You also have to accept the fact that sometimes, the most important things will be things that you are ordered to do, not necessarily the things that you feel the need to do. When this happens, argue vigorously, accept the orders of your superious, and plan for the "I told you so" contingency. That way, if it turns out that you were right all along, you're still in a position to fix the underlying problem.