Other Duties As Assigned

Your CV should reflect the work you did.  

Sometimes a job title is a good summary of the work you did, because the title implies the role, and the role implies the work.  But often titles are imprecise, or, even worse, wrong.

In the instance where you were hired as one thing (e.g., business analyst) but ended up doing another thing (e.g., product manager) from the start, you definitely should use Product Manager as your job title on your resume for that position.

But even then, titles are seldom enough to convey to future employers what you actually did.  The real substance is in the details below the title, which describe your main responsibilities, and what you achieved, while in the role.  That's the stuff to worry about getting right.  Those are the details that get you in the door for the interview.

• Make sure your responsibilities list is written in the same "language" as the job postings you are looking at.  Use the same key words, and the same categories of work.
• Make sure your achievements are measurable, concrete and demonstrated that you fulfilled the items you listed in your responsibilities.
• And keep your list for each position short.  A sentence for each of your top six to ten responsibilities, and a sentence for each of those that describes your achievements related to each one.