Integral Logistics Management — Operations Management and Supply Chain Management Within and Across Companies

20.3.9 Using the Hierarchical Constructs Based on Basic Ob­ject Classes: The Company-Wide Generic Object Model

Intended learning outcomes: Explain the basic object classes and possible subclasses (specializations) of an industrial company. Describe the concept of a company-wide data model, or generic model.



Figure 20.3.9.1 lists the most important basic data or object classes for an industrial company.

Fig. 20.3.9.1 Basic classes and possible subclasses of an industrial company.

"Small" classes at the last line of Figure 20.3.9.1 can be classes for which, because of their few attributes, it would not be worthwhile to be in a class of their own (such as stock location). But often what we are dealing with is only the definition of the domain, or value range, of the attributes (such as time allowed for payment, type of costs). The ID key of the class “code” is made up of a name and numbers organized according to some criteria. The set of attributes comprises, for example, two or three attributes, whose domain is a simple sequence of numerical or alphanumerical characters.

Together with the other kinds of hierarchy creation, creating association classes is a powerful tool for the development of operational information systems in a company. During the pre­liminary and main studies of the system, a company-wide data model or object model can be generated based on a few basic classes. One then speaks also of a generic model or generic objects. In the problem-solving cycle of systems engineering, this generic design process is a part of synthesis. For details, see here [Sche98a] or [Schö01, Sections 6.3 to 6.5].




Course section 20.3: Subsections and their intended learning outcomes

  • 20.3 Modeling Information Systems in the Data View and Object View

    Intended learning outcomes: Present terms such as object, attribute, object class, view, primary and secondary keys. Explain basic concepts such as association, association role and type. Describe the breaking up of an n-to-n association – in particular a reflexive one – and the association class. Disclose the use of the hierarchical constructs for developing a company-wide generic object model.

  • 20.3.1 Object, Attribute, and Object Class

    Intended learning outcomes: Differentiate between entity, object, and data record. Differentiate between attribute and data field. Differentiate between object class, file, and table. Explain the class customer as a table in the relational database model.

  • 20.3.2 View and Primary and Secondary Keys

    Intended learning outcomes: Produce an overview on the view on a class. Differentiate between primary key and secondary key. Describe characteristics for a “good” primary key. Explain the representation of a class in an object-oriented approach (with example) and the representation of an object.

  • 20.3.3 Association and (Association) Role

    Intended learning outcomes: Differentiate between binary association and reflexive association. Explain Abrial’s access function and the example of the association of the classes “book” and “customer” in library systems. Identify the (association) role.