Are these classes considered as boundary, or entity?

Question

I have these classes: IdCard, Note, Ingredient, Ceo, ProblemOccured, Chief.

In my opinion IdCard, Note, Ingredient and ProblemOccured are <<Boundary>> classes since they interact with the people.

But Ceo and Chief are <<Entity>> classes.

My friend disagrees with my understanding and I would appreciate if anyone helps.

Answer 1

Preliminary note

First of all, class names are always without :. The notation :CLASS is used in class diagrams, when a class name is used as type of a property. It is also often used, even without object/property name, for life-line in sequence diagram. The : means then an anonymous instance of class CLASS.

The classes to be analyzed are then: ID CARD, NOTES, IGREDIENT, CEO, PROBLEM OCCURED, CHIEF.

Some context

The Entity-Control-Boundary analysis pattern is based on use-cases. Without the corresponding use-cases, you cannot distinguish for sure between boundaries and entities. But we can make some assumptions:

• CEO, CHIEF and NOTES are apparently classes for long-lived objects.
• PROBLEM OCCURED could be a user-interface class to report an application problem. In this case it would be a boundary class. But it could as well be a problem that is reported by the chief to the ceo, which would make it an entity class.
• ID CARD could refer to an UI component to display the ID of an entity-person. In this case it would be a boundary class. But it could as well refer to an identity card, that contains all the informations of the identity document that is registererd in the application as entity.
• IGREDIENT: is it a typo of INGREDIENT (could be an entity, e.g. if it's an application and CHIEFs were in fact cooks) ? Is the starting I an I for "interface" (would be a boundary, but what is a GREDIENT) ?