If you aspire to the CIO role, it's time to get real about career development. Most people assume that when the time is right, they will have a good shot at getting the top IT job in their company. Sorry to say, but odds are that it's not going to happen.

If you don't believe me, consider your current CIO. It's almost a sure bet that he or she was hired into the position from outside the organization. When the time comes and you realize the top job is not coming your way, you will leave to get the CIO job at a smaller company or settle in as number two or number three—reconciling your lot while wondering why years of loyal and successful service were not enough.

You might think this is unfair, but there is a good reason that most companies go outside for their CIOs: Most of you aren't ready. In the lexicon of organizational development Ph.D.s, you haven't accumulated the necessary experiences. These experiences are derived from years spent in the right types of assignments.

To accumulate the right types of assignments yourself, you need to manage your career, not just your staff. Mentors are hard to find and most CIOs don't give succession development a lot of thought. I call this the unnatural selection process for CIOs. You can change this process, though, by asking for the right types of assignments at the right times in your career.

To get prepared for a CIO role, you have to learn the business of IT. The various IT lines of business (or functions) form an IT value chain, consisting of customers, relationship managers, developers, operators, service providers and staff.

If you want to become a good CIO, you need to work in most, if not all, of the IT functions because running IT is a matter of managing contending opposites—generating shareholder value while investing in the future while delivering great customer service while operating efficiently. If you limit your experience to a single function, such as applications development, you will have little understanding of the impact of technology footprint on operating costs, for example, or the relative importance of help desk service issues on the overall perception of IT.

That being said, not all IT lines of business are created equal. The business customers want to work with one of their own and therefore want CIOs who understand the business and have a proven delivery track record. That's why most CIOs hail from the application developer function. This is also why it's so important to gain experiences and exposure outside of IT: to learn the business and foster relationships with senior executives who will help sponsor your career.

While you are looking for opportunities that provide exposure to the various IT lines of business, also consider assignments that, by definition, are jam-packed with challenges. In his book High Flyers: Developing the Next Generation of Leaders, Morgan McCall identifies seven job assignments that often play an important role in leadership development. These are early work experiences, first supervision, start-ups, turnarounds, changes in scope, task force assignments and line-to-staff switch.

Early Experiences. From the start, you need to actively manage your career as an individual contributor. This is when it is easiest to move across the various IT lines of business and learn how to work with colleagues and managers who have different backgrounds than your own. As you advance up the career pyramid, crossfunctional moves become fewer and farther between.

First Supervision. Most executives wish they had more experience managing people earlier in their career—when their mistakes were not quite so visible. Look for early supervisory opportunities, even if it means moving to less glamorous roles (for example, from applications development analyst to help desk supervisor).

Start-ups. If you really want to understand the CIO role, find a start-up assignment in which you are expected to build something without instructions—for instance, integrating the systems from a newly acquired business, helping start up operations in a new country or creating a consolidated data center. These are roles that will challenge your ability to set goals, gain resources and support, and manage issues ranging from the strategic to the mundane.

Turnarounds. Almost every available CIO job has some aspects of a turnaround. You need to prove you can analyze the current situation and put a plan in place that will improve performance under tight time and budget constraints. To identify these opportunities, look for a customer who is unhappy, an expense that is out of control, or a project that is long overdue.

Changes in Scope. These are leadership roles that offer you new challenges in one or more of three components: the number of people managed, the level of financial accountability and the diversity of functions. These positions will test your ability to handle the unfamiliar and manage performance through others by "remote control." Within IT, most of these roles are in the operations and services functions. They are often overlooked by up-and-coming development managers as important areas to pursue for leadership development.

Task Force Assignments. One of the best ways to gain business knowledge and develop relationships outside IT is by working on a strategically important task force. It is likely that you will need to volunteer (and sell yourself) since task forces are usually run by non-IT leaders and your name will not be on the top of their list.

Line-to-Staff Switch. The IT staff functions define the rules for the rest of the IT organization; strategy, governance, standards, financial and headcount targets, processes and metrics fall under the staff "office of the CIO." Joining the IT staff will teach you how to influence others without formal authority, give you a (sometimes not so pleasant) birds-eye view into IT, and get you up-close-and-personal with the CIO, business executives and IT leaders.

Before you become a direct report to a CIO, try to make sure you have been exposed to multiple IT lines of business in challenging assignments that promote learning, self-awareness and relationships across the organization. This may mean that you forgo near-term promotion prospects and make lateral moves in your thirties to be positioned right for your forties. Understand that you will need to communicate your career development goals and the types of roles you would like, to be patient and to ask for feedback along the way.

Many a talented professional has been lured to a job only to find himself working in a dead-end role under a powerless executive. The best way to manage your career is to remain humble and look for the right skillbuilding experiences under the right leaders rather than jump at the first promotion that comes along.