My background:
BS in ChemEng
MS in Engineering Management (after working for 10 years)
Employed at a program and construction management company where my primary function is PM services to clients
I've been able to distinguish two distinct sets of skills required to be a project manager - I'll call them "project" skills and "manager" skills:
Project skills are technically based. These are the things that you can learn out of a book and often have software packages written to help you out. Some are fairly basic and all PM's should be able create and maintain the associate reports for tracking purposes during a project:
- work breakdown structures
- cost control (budgets, commitments, forecasts, actuals)
- scheduling
- scope of work documents
- contracts
(Contracts are an exception since these are often reviewed and edited by lawyers but PM's should be able to help guide the lawyers since contracts ultimately determine possible courses of action available in the case of outside firms used on a project.)
Other project skills are fairly advanced and not needed for the majority of projects a PM is normally asked to manage:
- discounted cashflow analysis with expected NPV
- optimization or simulation modeling
- decision trees
- cost reports tracking project spending by tax type (real property vs. personal property for instance)
- cost performance index and schedule performance index graphs
Many of these advance project skills are used when trying to figure out what type/scope of project to undertake. Most PM involvement occurs once this decision has already been made.
The other set of skills are the "manager" skills. These are soft skills that can be read about in books but really aren't learned until you've had a few projects completed successfully and had a few that blew up on you. (Not literally - just overran schedule, budget, etc. An actual explosion would let you learn other skills like litigation support.) This skill set continues to refine and improve with each new project you take on. RDK's advice on managing a team falls into this category and that "balancing wire" is something that changes with each new team and each new project. Other types of skills that fall here:
- motivation
- leadership
- influencing people without authority
- team building
- comminucation (this is a HUGE one)
A successful project manager needs elements of both skill sets - either one without the other ultimately doesn't work. I've seen far too many people that are great at working through schedule logic and managing activity durations but never communicate with the team so the schedule is meaningless.
As far as the PMI test to become a CPM (certified project manager), I've looked into it and had associates take it. From what I can see, it looks like something any experienced PM should be able to handle assuming they understand PMI's terminology. Be sure to look at the requirements for certification too - it's not just a test. You have to have experience as a PM just as someone taking the PE test needs to have documented engineering experience.
Good luck as you sort through things. I've found project management very rewarding and also very challenging. It forces me to draw on my technical experience in engineering and PM while also using those "soft" skills that many of us engineers are thought not to have...