I apologize for the length of this post (this turned out way longer than I thought it would!), but I want to make sure I cover everything before asking for responses.
I find myself in a bit of an awkward position regarding how to ask for a pay increase (a considerable pay increase at that). My justification for the proposed increase is related partly to my "normal" job performance, but moreso to the continuing evolution of my role within my department. I consider this to be serious enough that I would be willing to at least start the process of looking for another job if something doesn't change with my current situation. My annual performance review will be coming up within the next 4-6 weeks, and I figure now is as good a time as any to bring it up with my boss.
About 3 years ago, prior to entering my current position, I started working on a number of IT-related process improvement projects of my own initiative. My position is not an IT position, and there is no position within my area that is remotely related to IT; I just happened to be someone who knew how to do these things. My projects were very well received, and proved to be enormously useful throughout the department. As a result, I continued, on my own, to work on larger and more complex projects of a similar nature. After a year of this, I was promoted to my current position (not so much because of my technical abilities, but rather because of the problem solving skills and initiative those abilities allowed me to demonstrate).
I am currently a low-level manager with 10 directs. On top of my normal managerial responsibilities, I have continued to develop and maintain more and more sophisticated systems to handle our work, to the extent that there is now almost no process in the department that is not handled within something I have created. I can honestly say that after 3 years of this, the department is almost unrecognizable (in a good way) from what it was when I started doing this work. I don't want to be an arrogant jerk and say that I single-handedly did this, but I single-handedly did an awful lot of it. I can also say that almost none of this would have otherwise happened if I hadn't been there (that's obviously speculation, but it's reasonable speculation).
So my conundrum is this: all of the IT-related "stuff" I've been doing over the years is well above my pay grade, and is not in any way part of my job description or factored into my salary. I feel that it has gone from a "convenient extra thing on the side" to something where it's now fully expected that I'm going to continue to do this as a normal part of my job. This extra work now takes up at least 25-50% of my time, on top of my "regular" 8-hour-a-day managerial responsibilities. I handle this by routinely coming in on the weekends, working on things in my free time at home, and in general working a large amount of overtime.
I know that both my boss and skip consider me to be extremely valuable, and they mention this to me regularly (although whether that appreciation translates into money remains to be seen). If I were to leave it would be a significant blow to the department, as there is no one else there with these skills, and they would have a very difficult time finding someone simply to maintain what I've created, much less to fully replace what I bring to the table. Although there is no position in the department that requires these skills, at this point it would be considered critical that there is someone specifically within the department who can do what I currently do (utilizing our normal IT area to do this work wouldn't cut it, and my boss/skip are well aware of this). I receive glowing performance reviews every year, and fully expect to receive one this year as well.
At the end of the day, I believe the improvements that I've made (and continue to maintain and expand upon) save the department well into the six-figures every year, and this will continue to increase as our department continues to move further in this direction. I would not have a hard time substantiating this if I had to. If I'm being honest, I feel I should be getting paid anywhere from 30-50% more than I'm getting paid now. However, I don't want to go into the discussion with some crazy-out-of-the-question proposal for what I think my salary should be. At the same time, I don't want to undervalue myself.
I would appreciate any thoughts on how I should handle this (or if I'm being completely ridiculous in even asking for a pay increase, tell me that too!). Am I correct that it would be better to have this type of discussion prior to the beginning of the performance review?