I would like to present myself as a candidate for the Doctoral Program in Business Administration (concentrate in Information Systems) at the University of XXX.
I think the first paragraph is incomplete. In addition to stating your intention, you should give a sentence that expressed the main idea of the essay. The essay needs to have one unique idea, a theme that distinguishes it from the rest. This is not easy if you have not put enough thought into your plan for the future, but anyone who develops their plan will have a theme that is very unique, because you'll have a niche plan, a detailed plan, that reflects your unique interests and talents.
The whole essay does nothing but mention the experience that is already evident in your resume or transcript. The essay is not unique enough. In addition to this experience, you need a detailed plan, a specific plan. Think about what you want to do, and tell the reader why this program is better for you than other, similar programs. You should dig deep and really appeal to the reader on a personal level. Think about how you would talk to your mom or your friend about the school. What really makes this school best? Be a little personal, and you'll win the reader's heart.