This is a smart approach. It gives you insider information and it also puts you in a good position to apply for the job. Your boss already knows who you are and what kind of work you do. You can approach him personally about the job before he even receives other applicants. You will also already know all about the job because you trained people for it or for positions that were close to it. Perhaps you trained the person who is currently leaving, or you trained someone who worked with them. If you trained someone who worked with them you might have your way to get in; or you might have trained your own competition.
The only problem is you do not come as a big surprise to the boss. You do not come to him with the first impression of someone who is so impressive and deserving of the final dream job. The boss knows you as the trainer and might still see you as the trainer when you apply for the real thing. First impressions are lasting and can make a huge difference. If you first approach the boss and let him know you really want that job but are willing to train for a while until that job opens up, then they might see you in that light from the beginning. But if you simply apply for their training job and do not mention your intentions to climb into higher positions, they might forever see you as the trainer and nothing more. Some people have no imagination and have a hard time changing their perspective on people they already know. Think of all the legendary figures of history and how their closest friends and neighbors refused to see them as magnificent or great because they knew them when they were young and were still learning. People have a hard time seeing you differently once they have already assessed you.
First impressions are the most important when you are looking at jobs. So when you interview for that training position, you should consider the long-term goal while interviewing for that position. Be sure to represent yourself as a potential candidate for the dream job you really want. Be sure to let your boss know about your intentions. Make them clear and make him see you as a candidate for your dream job, not just another candidate for training jobs they have open. This might also set you apart and help you get the training job. If they see you as someone who will stick with their company, they might be more interested in investing their time to get you trained for a higher position. They will see you as a long-term asset to the company. So it is imperative you make your goals known from the beginning.
Training jobs can be fun at times. You get to see a lot of people come through. You meet all kinds of new people every day. You are the one they look to when they have questions about the company. So you might really enjoy that position while you are in transition to taking the position you really want. You will also most likely learn a lot from all those you train. Trainers always say they learn more than the actual trainees. They learn more about what they are teaching, but they also learn more about what that trainee knows and has to offer. There are often great friendships that form from these trainer/trainee relationships as well.
There are a lot of benefits to starting as a trainer in a company. You can get a good feel for how the company operates. You might see how they could better operate if you worked in a higher position for them. Or you might realize they are not the right company for you. You might change your mind and decide on another company once you see how this company operates. You might develop a friendship with your boss, or you might butt heads and realize that the two of you do not really see eye to eye. Training can be a way of testing the waters before you dive in. It might save you a lot of hassle later and prevent you from taking that final position only to realize it is not what you wanted after all.
Training jobs give you the opportunity to see the company firsthand and learn all about what they do. You teach all those who come into the company for the first time and get to learn all about those you train. You might develop great friendships with those you train, being their mentor when they first arrive. They might be nervous and in need of guidance, and you are there to give it to them. These are things they will not forget and they will most likely be very appreciative of it. Best of all, you will know exactly when your dream position will be available. You might know ahead of time, right when the person vacating the position puts in their two weeks’ notice. So hopefully, you will be ready when that time comes.