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

Basic classPossible subclasses (specializations)
Business partnerCustomer, supplier
ItemFinished product, semi-finished item, raw material, indirect material
TimeDate, calendar, clock time
PersonSalaried employee, blue-collar worker
CapacityInternal (assembly, parts production, warehouse), external
Capital assetReal estate, site, machine, device, tool
LocationWarehouse location, production location, workstation
AccountFinancial account, operating account
Numbers/CountersBill-of-material position, routing sheet number, routing sheet position, parameter number, sequence number
Code(This class generalizes many "small" classes)

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

"Small" classes at the last line of Figure 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.

  • 20.3.4 Single-Valued and Multivalued Roles, and Total and Partial Roles

    Intended learning outcomes: Differentiate between a single-valued role and a multivalued role. Differentiate between a total and a partial role, or access function.

  • 20.3.5 Association Types

    Intended learning outcomes: Differentiate between the 1-to-1 association, the 1-to-n association, the n-to-1 association, and the n-to-n association. Explain various examples of different binary associations.

  • 20.3.6 Breaking up an n-to-n Association; Association Class

    Intended learning outcomes: Explain the association class formed by breaking up an n-to-n association into a 1-to-n association and an n-to-1 association.

  • 20.3.7 Different Notations and the Reidentification Key

    Intended learning outcomes: Describe the commonly used crow’s-foot notation for depicting associations in the entity-oriented approach. Identify the common notation for associations in the entity-oriented approach. Explain the Representation of associations in an object-oriented form, as well as the concept of the reidentification key.