I was given a conceptual model where Object A is Object B, e.g a DIYedPC is a Product for a online PC DIY shop, or a CustomizedSoftwareKit is a Product for a online software customization shop.
So how do you usually model this kind of IS-A relationship? Will you design Class A as a variable member of Class B (i.e. B's instance is holding a reference to A's instance)? Or will you use the 'Item-Descriptor Pattern' / 'The Type Object Pattern' to model the relationship as B describes A?
There is a specific symbol in the UML for showing an concrete inheritance relationship. On a Class diagram you would use this symbol to connect the Sub and Super classes. In Java, this is implemented with the "extends" keyword.