Value binding is the method to maintain values of properties, which are bound together, to be the same. The properties whose values are bound, must be connected together with a connector. The type of the properties which are bound together must be the same or one is a subtype of another. If the type of the properties is a primitive type, you can bind them with either a UML connector that does not have a type, or a SysML binding connector with a «BindingConnector» stereotype applied. If the type of the properties is a class or a block, you can only use a SysML binding connector to tie them.