Job analysis is just that — analyzing the tasks you need done so that you can create just the position you need. It doesn't have to be difficult or complicated. Job analysis is the process of looking at exactly what a job entails in order to determine the necessary job qualifications.
Is a job analysis required to determine job qualifications? No, but remember that planning is the key to successful, effective, and cost-effective hiring. The better you know what you need in an employee, the more likely you are to find the right candidate. Doing a job analysis is just a formal documentation of an unconscious thought process that you should go through anyway. It's a great first step toward creating a job description.