Relation between 2 dimensions

Hi
Not sure whether the one which i posted yesterday was posted or not ...not able to find that.

Before i start i would like to let you know that i searched through all messages and i am not finding what i want

I have 2 dimensions 1.Agent 2.Policy(insurance domain) an agent can own many policies sold by his/her to many customers and will be getting commission whenever premium is paid.Its also possible that a policy can be moved /tranferred from one agent to another agent,now i want to maintain the relationship between the 2 dims so that at any point we would be in a position to what agent is having what policy.I came to know that this can be done with the help factless fact but i want to get some expert opinion so i am not overlooking the details.Also if you can share some sample table structure it would be of great help.

When we have to make an entry in the table.Is it when the Agent changes or Policy changes.Agent is higher grain than Policy

Is this need to be captured at the end of time period such as end of week or end of month .

Please let me know what is the best practice and what are the things should be considered while designing this table structure.Please throw some light on this

A factless fact table is typical for tracking such things. You probably want to include effective and expiration dates as dimensions (degenerate or otherwise) as well.