kilger@NewYork.ira.uka.de (Christoph Kilger) (04/22/91)
Hello!
Does anybody knows about a
graphical specification method
for
object oriented modelling ?
The problem with object oriented modelling is the integration of
structural and behavioral properties. That is why classical semantic
data models, i.e., the Entity Relationship Model, cannot be used for
object oriented design.
We have build the object oriented database system GOM that is used by
several groups, e.g., of the engineering domain, at the University
of Karlsruhe. These user groups enquire for a graphical method
that will be used
(1) for the documentation of object oriented database schemas, and
(2) for the specification of new applications.
If you have developed such a method or know about one,
please contact me.
Christoph Kilger,
IPD, Univ. Karlsruhe,
7500 Karlsruhe, Germany.allen@manic.ssc.gov (Mike Allen) (04/22/91)
>>>>> On 22 Apr 91 07:33:28 GMT, kilger@NewYork.ira.uka.de (Christoph Kilger) said: In article <1991Apr22.073328.7858@ira.uka.de> kilger@NewYork.ira.uka.de (Christoph Kilger) writes: Christoph> Originator: kilger@i40s17 Christoph> Hello! Christoph> Does anybody knows about a Christoph> graphical specification method Christoph> for Christoph> object oriented modelling ? We are starting to use: "Object-Oriented Modeling and Design", by James Rumbaugh, Michael Blaha, William Premerlani, Frederick Eddy, and William Lorensen. I don't know of any case tools that directly support their notation, however. Does any one else? -- =============================================================================== Michael E. Allen Mail Stop 1046 SSC Laboratory 2550 Beckleymeade Ave. Dallas, TX 75237 (214)708-3031 al tadin et khaverkha 'ad shetagi'a limkomo -Ethics of the Fathers Do not judge your fellow man until you have come to his place.
haim@taichi.uucp (24122-Haim Kilov(L028)m000) (04/28/91)
In reply to: The problem with object oriented modelling is the integration of structural and behavioral properties. That is why classical semantic data models, i.e., the Entity Relationship Model, cannot be used for object oriented design. --the first sentence is correct, whereas the second is not. ER model, actually, deals with behavioral properties, although they are very simple ones: after all, consider the precise definitions of such concepts as "relationship", "dependent", "composite", etc. These definitions will be based on primitive (CRUD) behavior of the particular entity and associated entities, i.e., on operations jointly owned by these "clusters" of entities. I have published a paper in TOOLS'91 on this topic, and we have also published an extended Bellcore Special Report about this (I mentioned this some time ago in comp.object). On the other problem -- graphical representation of object classes -- I can only say that it is difficult: the ER approach provides only a partial answer, and you still need different graphical representations for different kinds (meta-types) of entities. Still, it's a reasonably good approach. The problem of more application-specific behavior is more difficult. Are you absolutely sure that a graphical representation will help? After all, I agree with Bertrand Meyer: A picture is worth thousand words, but did you try to find seven errors in a picture? Hope this helps. -Haim Kilov haim@bcr.cc.bellcore.com
pt@well.sf.ca.us (Neil Lang) (05/01/91)
In article <1991Apr22.073328.7858@ira.uka.de> kilger@NewYork.ira.uka.de (Christoph Kilger) writes: > Does anybody knows about a > graphical specification method > > for > object oriented modelling ? > > > The problem with object oriented modelling is the integration of > structural and behavioral properties. That is why classical semantic > data models, i.e., the Entity Relationship Model, cannot be used for > object oriented design. ....................... > > Christoph Kilger, > > IPD, Univ. Karlsruhe, > 7500 Karlsruhe, Germany. Shlaer-Mellor Object-Oriented Analysis (OOA) is a modeling method that directly addresses the needs mentioned above. OOA is summarized in a paper "An Object-Oriented Approach to Domain Analysis" by Sally Shlaer and Stephen Mellor, Software Engineering Notes ACM Press July 1989. The first of the 3 sets of models in OOA is the Information Model and almost everything you might want to know about IM is covered in their book "Object-Oriented Systems Analysis: Modeling the world in Data" Prentice-Hall 1988. The sequel "Object Lifecycles: Modeling the World in States" will be available later this summer. There are a small set of CASE tools that support various parts of OOA. In particular Teamwork by Cadre supports all three models that make up OOA. -------------------------------------------------------------- Neil Lang pt@well.sf.ca.us Project Technology 2560 Ninth Street, Suite 214 Berkeley CA 94710 415-845-1484 ---------------------------------------------------------------
nic@mrcu (Nick Chapman) (05/03/91)
>The first of the 3 sets of models in OOA is the Information Model and >almost everything you might want to know about IM is covered in their >book "Object-Oriented Systems Analysis: Modeling the world in Data" >Prentice-Hall 1988. What has this book got to do with Object Oriented analysis ? -- absolutely nothing. In my opinion this book consists entirely, of a shallow description of the information model, and a technique that is just Structured Analysis with a new name. Look at the useful advice it gives on how to find the objects contained within a system, which surely is the fundermental problem : It is assumed that you know the approximate "center" of the problem domain, and you will start there to identify objects. If you can't identify the center, start anywhere and just keep working. (Section 9.2.1) > The sequel "Object Lifecycles: Modeling the World >in States" will be available later this summer. Can't wait !! .Nick. -- ------------------------------------------------------------------------------- Nick Chapman, GEC-Marconi Research Centre | INTERNET: nic@uk.co.gec-mrc Great Baddow, Chelmsford, Essex. CM2 8HN | Tel: +44 245 73331 x3245 -------------------------------------------------------------------------------