public void Add(GroupPeople groupPeople) { //Go to GroupPeopleRepository, add the new groupPeople and return the (new) GroupPeopleID repository.Add(groupPeople); //Go to AssetOwnerRepository and add a new Owner by adding the GroupPeople(ID) repositoryAssetOwner.AddAssetOwnerGroupPeople(groupPeople.GroupPeopleID); //no need to return anyting, that's why here keep void! }