The question came up whether you play the role of business analyst differently if you are a project manager or some other position. The answer is a clear ‘yes”. This is mostly because as a business analyst you are analyzing the business full time. In some other position the role is an addendum or an incidental part of your full time job. A project manager is paid and rewarded for the success of the project, bringing it in on time, within budget and fully featured (everything done that was promised for that time frame and budget). So when prioritizing her activities, the emphasis is going to be on tasks that contribute to project success. The business analyst will seek out different ways to solve the business problem and improve the business process while another position might ignore or avoid adding more to the project or other responsibilities.
Business analysis is a full time concentration. It requires attention to detail and looking at the big picture, sometimes simultaneously. It requires a specific attitude and approach. It is not an afterthought or simply the recording of what the business might want the computers to do at this moment.
Those who perform business analysis full time as their primary job are going to do it differently than those whose primary focus lies elsewhere.