Cardinality error,,, or snowflake schema needed?

[Kanellno]

Hi,

I got stuck in making Snowflake Schema. 

Can anybody help me, how to develop for Cardinality with correct order please?

Its part of my invoice. 

I was going to calculate only sales by Service Group. 

Product Dimension

Product Code Product Group  Product Service           Service Group

A

Air

COACH

ECONOMY (Air)

A	Air	BUSINESS	BUSINESS (Air)
A	Air	PREMIUM ECONOMY	PREMIUM ECONOMY (Air)

R	Rail	BUSINESS	BUSINESS (Rail)
R	Rail	COACH	ECONOMY (Rail)
R	Rail	Rail	ECONOMY (Rail)

Fact Dimension

Product Code	Product Group	Product Service
A	Air	COACH

R

Rail

BUSINESS

In Product Dimenstion, I newly inserted the column Service Group, which doesnt exist  in FACT Dimension. 

The problem, is that I can not make one to many cardinality. so, i guess, i need Snowflake schema. 

But, I do not have another column and data in terms of the product above in Fact dimension (invoice). 

[bcdobbs]

Your fact table is at a different grain to your dimension table.

If you can't change the grain of the fact table I would use a many to many relationship set so the dimension table filters the fact table.