The question we ask here is whether you can be too specialized or if there will always be opportunities available to you. More importantly what actions do you need to consider in order to get the best results.
With the increasing complexity of business, especially in the information technology fields and other technical disciplines, it is common for may people to be labeled as a specialist. All you have to do is be good at something the company needs done. Then they will want you to do that rather than anything else. There is nothing wrong with that, unless and until you attempt to find a new job and meet the objection that you are too much of a specialist. Fortunately, when you look at substance and not labels, this is most often not a legitimate objection, and you can deal with it in a number of ways.
Remember that most "specialists" are in fact people who do a number of things well, but in their attempt to be good employees and do what the organization needs done, for some selected period of time, they do one particular thing more often than any other. This does not mean they are any less proficient in the other skills and functions, just that they haven't applied them frequently for that period.
Keep in mind that, at any given moment, each of us brings to the table the talents and knowhow developed over several types of positions. Your non-specialist experience, regardless of when it was developed, is just as valid and applies just as fully in the present. The specialist experience no doubt adds to your appeal, but it need not overshadow other capabilities and strengths that an employer would value.
Use a format that emphasizes experience and achievements in as many functions as possible. In even the most specialized positions, there are several functions, e.g., analysis, communication, team interaction, creative problem solving, project management, etc., and there might also be achievements that relate to other fields, e.g., productivity increases, finding new and better methods, implementing change smoothly, leading by example, building new capabilities, working with others to produce outstanding results, etc.
Use a summary up front that emphasizes your versatility and adaptability, as well as the fact that you are quick to learn new functions and master difficult technical material, where that applies. If on one or more occasions you faced change, adjusted quickly, and went on to deliver results equal to or better than those who'd been in the function a long time, be sure to emphasize that. Throughout the resume, avoid using any terms or jargon that will over-identify you with a specialty.
Interviews / e-mail / Letters
Think in terms of "Why should people want to hire me?" and "What have I accomplished that would show my potential for delivering results to this new employer?" When you do, you will appreciate that the best interview strategy is to ask questions about the functional skills and personal traits that would be most important in the job, and then relate stories in a situation-action-result format which show that you have used those skills and traits effectively to achieve results.
It will also help to have stories to back up the point on your resume, that you have faced change before on a number of occasions and fared quite well. Also, be ready to introduce into the discussion additional strengths and experience areas where you have an edge, and show how they could enhance your performance in the position.
In any correspondence or interviews, it helps to know as much as possible about the company and the industry beforehand, and to express a lot of enthusiasm for the job. In general terms, the more ways that you can show you are a good fit for the position, the better your chances.
If there is a course you can take, or information you can study, that would help prepare you or make you more knowledgeable about the type of position you are targeting, get started on that as soon as possible. If you can talk with people in that field, arrange to meet with them and get their input. If there is a trade or professional publication geared to that field, subscribe to it or read back issues in the library. If there is one time when being a specialist does not hurt, it is having specialized knowledge in the field you are targeting. This is one way to get it.
Conduct research on any industry and companies you are targeting, using the Internet and/or resources in the Business Reference section of a good library. You might even consider going so far as to write a small article about the major trends in that industry as they affect someone in the job function you are targeting, whether it is purchasing, sales, production, marketing, finance, customer service, information systems, or any other function.
In this way, if you're short on results and achievements that relate directly to the position you seek, you can make up for it not only by emphasizing functional skills and personal traits, but also extensive knowledge about the industry and/or company. This also demonstrates a lot of enthusiasm, which is always a factor in a hiring decision.
Examine your contributions closely, and prepare several action-oriented stories that get across your talent for adapting and moving rapidly to get results in new situations. Be prepared to give as much evidence as possible in memorable stories. This will reassure the prospective employer about your ability to deliver in a function that is broader than or different from your current position.
Develop and coach enthusiastic references from inside your employer organization if possible, as well as outside, e.g., customers, suppliers, sales reps, consultants, etc., who will be happy to attest to your ability to learn quickly and adjust to new situations, and to your experience in a variety of functions. Review your resume with them, and make sure they keep a copy available for reference when and if they are called.
This step will enable you to make the statement in an interview that, "You've heard about Joe Smith from Joe Smith, but you really need to hear it from some of the people who know me best, and I strongly urge you to call them." That will erase any lingering doubts that you might be too specialized.