Issue 15077: Constraining a decomposition hierarchy (sysml-rtf)
Source: INCOSE (Mr. Sanford A. Friedenthal, safriedenthal(at)gmail.com)
Nature: Enhancement
Severity: Critical
Summary: There is a need for a robust mechanism to constrain a system decomposition hierarchy to reflect only selected groupings of parts as motivated by the following example. In particular, assume a rack assembly is composed of a chassis and a set of circuit cards. The rack assembly is constrained by which cards can be inserted in which slots. This includes an optical card in an optical slot, an ethernet card in an ethernet slot and a general slot that can accommodate either an ethernet card or an optical card (source is Nathan Sowatskey example). In addition, a particular rack configuration may include a specific number of each type of slot and card. The need is to constrain the hierarchy to only allow these combinations parts. Generalization sets, redefinition, and other mechanisms can help, but require considerable modeling that is cumbersome. The desired capability is to be able to include a constraint in the rack assembly that constrains the allowable instances of the rack assembly. It is also desirable to specify constraints on nested parts using the dot notation. (Refer to related issue 14998 binding to multiplicity in parameterics).
Resolution: 
Revised Text: 
Actions taken:
February 20, 2010: received issue
Discussion: 
This issue is being deferred because no proposed resolution was voted on during
the schedule of the SysML 1.3 RTF.
Disposition: Deferred
End of Annotations:=====

m: webmaster@omg.org
Date: 20 Feb 2010 14:51:56 -0500
To: <issues@omg.org>
Subject: Issue/Bug Report


*******************************************************************************
Name:          Sanford Friedenthal
Company:       Lockheed Martin
mailFrom:      sanford.friedenthal@lmco.com
Notification:  Yes
Specification: SysML
Section:       8
FormalNumber:  formal/2008-11-02
Version:       1.1
RevisionDate:  Nov 2008
Page:          31-59
Title:         Constraining a decomposition hierarchy
Nature:        Enhancement
Severity:      Critical
test:          3qw8
B1:            Report Issue


Description:

There is a need for a robust mechanism to constrain a system decomposition hierarchy to reflect only selected groupings of parts as motivated by the following example. In particular, assume a rack assembly is composed of a chassis and a set of circuit cards. The rack assembly is constrained by which cards can be inserted in which slots. This includes an optical card in an optical slot, an ethernet card in an ethernet slot and a general slot that can accommodate either an ethernet card or an optical card (source is Nathan Sowatskey example). In addition, a particular rack configuration may include a specific number of each type of slot and card. The need is to constrain the hierarchy to only allow these combinations parts. Generalization sets, redefinition, and other mechanisms can help, but require considerable modeling that is cumbersome. The desired capability is to be able to include a constraint in the rack assembly that constrains the allowable instances of the rack assembly. It is also desirable to specify constraints on nested parts using the dot notation. (Refer to related issue 14998 binding to multiplicity in parameterics).