Ordinary is a type of Charge. Assessment is a type of Charge. 
Mom is related to Dad. Dad is related to Husband. Husband is related to Married. Married is related to Father. 
Ordinary --IsA--> Charge <--IsA-- Assessment 
Mom <--RelatedTo--> Dad <--RelatedTo--> Husband <--RelatedTo--> Married <--RelatedTo--> Father 