The ER diagram has been introduced by P. Chen in 1976 [Chen76] and has been widely used for conceptual data modeling ever since.Today, there are many variants of the ER diagram, four of them are available in ARIS (see Figure 1).
Figure 1: ER diagrams in ARIS
The following table exposes which object types can be found in which ER diagram.
When looking closely at this line-up, you can see the main differences between the ER model types in ARIS: the eERM uses the object type “relationship type” to model relationships between entity types. This object type is missing in IE data model, SAP SERM and SeDaM model, where relationships are represented by connection lines.
Another difference apparently refers to the modeling of attributes and their domains. This conclusion, however, is rather erroneous because all object types that may have attributes (entity type and relationship type) can be detailed by an eERM attribute allocation diagram.
The ER object types listed in the above table can be assigned to three layers representing different levels of detail (see Figure 2).
Figure 2: Hierarchy of ER object types
In my future articles I will explain the following ER model types in more detail:
- eERM
- eERM attribute allocation diagram
- IE data model
- SAP SERM
- SeDaM.
Remember: Your contribution is highly appreciated. Feel free to share your experiences with the ARIS Community.
Tue, 01/08/2013 - 15:51
We discussed this topic some years ago and decided to use the object type “Cluster/data model” instead of “Technical term” to represent data/information objects, especially as input/output in process models at the business layer.
“Technical terms” represent the terms/the terminology used in an organization. Technical terms do not only refer to data/information objects.
We use the Technical terms model to build up the glossary of an organization with its terms and the relationships between these terms (e.g. Synonym (preferred term of), is part of, …).
Wed, 02/06/2013 - 07:21
Hi I agree Eva when she says,
Technical Term are used to buid a gloassary.
Data Clusters are used as input and output in Business View.
Why is it not posible to assign an ERM model to an Entity Type ?
Which model should I use to detail an Entity in a model in which i'm able to represent :
1 - The Entity (Ex : Process)
1 - Entity Attributs (Ex : Process Type)
2 - Link a enumaration to an attribut (Ex : Management, Operational, Support)
For exemple :
I have an Entity called Process, with an attribute Process Type and an enumaration of three process type : Management, Operational and Support.
Thank you for your help.
Pierre
Tue, 05/28/2013 - 08:29
