Q:

Shall I use my project management style when I'm substituting for my colleague, while he is away?

It is vacation period again, and I was asked to help out with a project while my colleague was on vacation. I don't know too much about the project - unfortunately we aren't that transparent -, but I know the people involved - we are located in the same area -, and I know the technology.
The way, I'm approaching project management problems, differs from the way, how my colleague does it. There's nothing wrong with this, because I believe that an organization needs diversity on certain levels, but now this diversity will appear in a project and only for a short amount of time, and this concerns me a bit.
For example, there's a meeting style in place, which I consider as not effective, but the colleagues are fine with it. If I change this, it will cause some disturbance in the projects life, which can be good for the project (they'll learn something new), or can be a risk (they'll slow down). This is not just about this particular meeting, there is the responding to emails, delegation, authority, saying no, saying yes and the list goes on.
I cannot switch between styles as fast as I would like, so I'm not quite sure how to proceed. Shall I use my style? Shall I follow my colleagues style, although I don't agree with it?

A:

My answer is a little different than Pawel's. I'd advise to replicate the other PM to the degree possible and only in a crisis would I deploy what comes intuitively to me. 
I revert to my machine analogy. When you replace a part you need it to fit the machine. Else the machine will not run or run well. 
Remember teaming theory, too. When a member is replaced, the team and its performance suffers. If you change things purposely, you are exacerbating this. 
Another factor to consider is the Hawthorne Effect.  This theory was based on a study that showed performance increases caused by some variable change, not because the variable actually caused the change but instead because the workers knew some change took place.  This gives a false cause and effect.  Eventually, the performance returned to its baseline state.  
A change offered by the covering PM may provide a similar result, where performance increases or even the team claiming this is better, but in fact has no more efficacy than the original way.  This will set up the vacationing PM when (s)he returns and I don't think any of us would like to deal with things like that when we simply go on vacation.  
Status quo is your best bet with the best odds and is the most respectful to the vacationing PM!

A:

There's one simple approach that usually is win-win.
Employ your style of running projects as your basis as it brings fresh air to the way team works. They can appreciate different style or just pick a couple of things they like or prefer the other PM more and appreciate him/her when he/she is back. Either way it should be fine. See more about role of fresh blood in terms of triggering improvements here and here.
At the same time respect any important and long-term arrangements that were made by the PM you are substituting. You don't want to change team's course heavily. You don't want to mess with the work the other PM did with the team. For example I wouldn't try to start the adoption on a completely new PM approach, etc.
Whenever there's a conflict between these two I would rather let the latter win over the former and then eventually when the other PM is back start a discussion about the ideas you have on potential improvements.

