UML 2.6 RTF Avatar
  1. OMG Issue

UMLR — The example in Figure 18.11 is badly designed in multiple ways and is strongly misleading

  • Key: UMLR-168
  • Legacy Issue Number: 13859
  • Status: open  
  • Source: University of Kassel ( Michael Zapf)
  • Summary:

    The example in Figure 18.11 is badly designed in multiple ways and is strongly misleading. Although it serves to explain the package import, it should not suggest an improper application of stereotypes. The stereotype defined here (Device) holds attributes which are not typical for devices as such. For instance, a device is not expected to have a color or volume. It may make sense to apply this stereotype to a class of TVs, but not to a class of dishwashers, for example. A better disctinction would be electrical versus non-electrical devices, or handheld versus non-handheld. Second, the attributes as shown here refer to properties which are significant for instances, not for classes. The example basically shows that we can create a TV class, declaring this to be a device. The Factory package shows an instantiation, setting the volume to some value, but omitting the remaining attributes - which must be set as well. The volume parameter for a class of TVs is questionable - what should it mean? This may lead the reader to believe that the volume parameter is meaningful for instances of the model element, although it is associated to the stereotype instance which is associated to the model element. Basically, the element in the Factory package denotes the class of all TVs whose volume is set to 10. This still does not imply a meaning for the instances.

  • Reported: UML 2.2 — Thu, 9 Apr 2009 04:00 GMT
  • Updated: Fri, 6 Mar 2015 20:57 GMT