This for Systems Analysis and Design in a Changing World course.
Consider that a real estate listing goes through several different states over time. For example, it might be a new listing, a revised listing, an under contract listing, a sold listing, and a removed listing. Draw a state machine diagram for a listing object based on this information. Include transition names and be sure to consider all of the possible transitions. For example, can a new listing transition directly to an under contract listing?