models.rb

class Asset < ActiveRecord::Base
  has_many :service_assignments
  has_many :services, :through => :service_assignments
  has_many :functions, :through => :services
  has_many :clusters, :through => :services
end
 
class ServiceAssignment < ActiveRecord::Base
  belongs_to :asset
  belongs_to :service
end
 
class Service < ActiveRecord::Base
  belongs_to :cluster
  belongs_to :function
end
 
class Cluster < ActiveRecord::Base
  has_many :services
  has_many :assets, :through => :services
end
 
class Function < ActiveRecord::Base
  has_many :services
  has_many :assets, :through => :services
end