RE: [SysML Forum] Multiple element instances in a deployment diagram
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edi...@sysmlforum.com
Oct 14, 2009, 8:36:28 PM10/14/09
to sysml...@googlegroups.com, UMLf...@googlegroups.com
Hello Paul,
The questions you pose conflate modeling language and tool issues, so in
my reply I will endeavor to separate the two.
> I would like to be able to have multiple instances of an element
> (node, device, etc.) in a deployment diagram (for example, multiple
> client stations connected to a server).
First, we need to clarify that Deployment diagrams are part of the UML
language rather its SysML dialect, where SysML is defined as a UML
Profile. (For this reason I am cc-ing my response to the UML Forum, so
that other UML experts can also contribute to this thread.) In addition,
the lack of complete Instance semantics in SysML is a critical language
design flaw, which was noted before the language was formally adopted by
the OMG, but which has not yet been corrected. (If you want to
understand this critical design flaw better, please let me know and I
will be glad to elaborate.) On the other hand, the lack of Deployment
diagrams in SysML can be viewed as a design virtue rather than a flaw,
since deployment relationships (cf. structure-to-structure allocations)
can be easily defined in SysML by defining appropriate stereotypes for
selected SysML structural elements and allocation dependencies.
You are correct that, according to the UML specification, you should be
able to define multiple instances of Nodes, Components, or other
allowable Classifiers on a UML Deployment diagram.
> I am using EA and it, at least, will not let me do so. Is there a way to get around this or do
> what I want to do?
There is no need for a workaround in Enterprise Architect (EA) since for
the most part EA's Instance syntax and semantics comply with the UML
specification. I use most of the mainstream UML/SysML modeling tools
frequently, including EA, and I just double-checked this capability
using EA v. 7.5 Deployment diagrams. It works fine! I suspect you may be
confused by, or misusing, EA's "Paste Element" dialog. When
copy-and-pasting a Node or other allowable Classifier (non-instance)
Element from the Project Browser to the target Deployment diagram, you
need to click on the second radio button labeled "an Instance of Element
(Object)" rather than the first radio button labeled "as Simple Link".
The former will allow you to define multiple instances of a Node or
other Classifier, the other will not since it is a reference link, not a
bona fide Instance.
> I'd also like to represent two (or more) environments separated by
> time. These would represent sequential aspects of a workflow (from a
> deployment perspective). ...
You are correct that chronologically ordering Instance "snapshots" can
be a useful way to compare and contrast environments as they evolve over
time. Here, however, I suspect you may encounter problems with how EA
handles Instance semantics over time, since this is a relatively
sophisticated technique.
/Cris
__________________________________________________
Cris Kobryn
Editor, SysML Forum
mailto:edi...@SysMLforum.com
www.SysMLforum.com
> -------- Original Message --------
> Subject: [SysML Forum] Multiple element instances in a deployment
> diagram
> From: Paul Ebert <a2e...@gmail.com>
> Date: Wed, October 14, 2009 6:36 am
> To: SysML Forum <sysml...@googlegroups.com>
>
>
> I would like to be able to have multiple instances of an element
> (node, device, etc.) in a deployment diagram (for example, multiple
> client stations connected to a server). I am using EA and it, at
> least, will not let me do so. Is there a way to get around this or do
> what I want to do?
>
> I'd also like to represent two (or more) environments separated by
> time. These would represent sequential aspects of a workflow (from a
> deployment perspective). An example might be a sales person on the
> road, giving presentations and gathering customer data at customer
> sites and then connecting to the home office network at the end of the
> day to load the data into an application or to access email. Again,
> in this situation, I'll need multiple instances of an element (well,
> they are actually the same instance at the abstract level, but are
> multiple instances from the tool's perspective).
>
> Any suggestions? Thanks.
>
>
The questions you pose conflate modeling language and tool issues, so in
my reply I will endeavor to separate the two.
> I would like to be able to have multiple instances of an element
> (node, device, etc.) in a deployment diagram (for example, multiple
> client stations connected to a server).
First, we need to clarify that Deployment diagrams are part of the UML
language rather its SysML dialect, where SysML is defined as a UML
Profile. (For this reason I am cc-ing my response to the UML Forum, so
that other UML experts can also contribute to this thread.) In addition,
the lack of complete Instance semantics in SysML is a critical language
design flaw, which was noted before the language was formally adopted by
the OMG, but which has not yet been corrected. (If you want to
understand this critical design flaw better, please let me know and I
will be glad to elaborate.) On the other hand, the lack of Deployment
diagrams in SysML can be viewed as a design virtue rather than a flaw,
since deployment relationships (cf. structure-to-structure allocations)
can be easily defined in SysML by defining appropriate stereotypes for
selected SysML structural elements and allocation dependencies.
You are correct that, according to the UML specification, you should be
able to define multiple instances of Nodes, Components, or other
allowable Classifiers on a UML Deployment diagram.
> I am using EA and it, at least, will not let me do so. Is there a way to get around this or do
> what I want to do?
There is no need for a workaround in Enterprise Architect (EA) since for
the most part EA's Instance syntax and semantics comply with the UML
specification. I use most of the mainstream UML/SysML modeling tools
frequently, including EA, and I just double-checked this capability
using EA v. 7.5 Deployment diagrams. It works fine! I suspect you may be
confused by, or misusing, EA's "Paste Element" dialog. When
copy-and-pasting a Node or other allowable Classifier (non-instance)
Element from the Project Browser to the target Deployment diagram, you
need to click on the second radio button labeled "an Instance of Element
(Object)" rather than the first radio button labeled "as Simple Link".
The former will allow you to define multiple instances of a Node or
other Classifier, the other will not since it is a reference link, not a
bona fide Instance.
> I'd also like to represent two (or more) environments separated by
> time. These would represent sequential aspects of a workflow (from a
> deployment perspective). ...
You are correct that chronologically ordering Instance "snapshots" can
be a useful way to compare and contrast environments as they evolve over
time. Here, however, I suspect you may encounter problems with how EA
handles Instance semantics over time, since this is a relatively
sophisticated technique.
/Cris
__________________________________________________
Cris Kobryn
Editor, SysML Forum
mailto:edi...@SysMLforum.com
www.SysMLforum.com
> -------- Original Message --------
> Subject: [SysML Forum] Multiple element instances in a deployment
> diagram
> From: Paul Ebert <a2e...@gmail.com>
> Date: Wed, October 14, 2009 6:36 am
> To: SysML Forum <sysml...@googlegroups.com>
>
>
> I would like to be able to have multiple instances of an element
> (node, device, etc.) in a deployment diagram (for example, multiple
> client stations connected to a server). I am using EA and it, at
> least, will not let me do so. Is there a way to get around this or do
> what I want to do?
>
> I'd also like to represent two (or more) environments separated by
> time. These would represent sequential aspects of a workflow (from a
> deployment perspective). An example might be a sales person on the
> road, giving presentations and gathering customer data at customer
> sites and then connecting to the home office network at the end of the
> day to load the data into an application or to access email. Again,
> in this situation, I'll need multiple instances of an element (well,
> they are actually the same instance at the abstract level, but are
> multiple instances from the tool's perspective).
>
> Any suggestions? Thanks.
>
>
Axel Reichwein
Oct 15, 2009, 3:48:06 AM10/15/09
to sysml...@googlegroups.com
Hello SysMLforum,
Chris, you mention that you could elaborate on the missing instances in
SysML. Could you please do so, as I would be very curious to know the
pro/contra arguments. Personally, I intensively use UML and can hardly
jump over to SysML, which would be in several aspects more appropriate,
since there is no support for instances in SysML (...to my knowledge, I
am not a SysML expert).
Best regards,
Axel
edi...@SysMLforum.com schrieb:
--
Dipl.-Ing. Axel Reichwein
Universität Stuttgart
ISD, Institut für Statik und Dynamik der Luft- und Raumfahrtkonstruktionen
Pfaffenwaldring 27, D-70569 Stuttgart
Telefon: +49-711/685-69531
E-mail: reic...@isd.uni-stuttgart.de
Web: www.isd.uni-stuttgart.de
Chris, you mention that you could elaborate on the missing instances in
SysML. Could you please do so, as I would be very curious to know the
pro/contra arguments. Personally, I intensively use UML and can hardly
jump over to SysML, which would be in several aspects more appropriate,
since there is no support for instances in SysML (...to my knowledge, I
am not a SysML expert).
Best regards,
Axel
edi...@SysMLforum.com schrieb:
Dipl.-Ing. Axel Reichwein
Universität Stuttgart
ISD, Institut für Statik und Dynamik der Luft- und Raumfahrtkonstruktionen
Pfaffenwaldring 27, D-70569 Stuttgart
Telefon: +49-711/685-69531
E-mail: reic...@isd.uni-stuttgart.de
Web: www.isd.uni-stuttgart.de
Dragos DOBRE
Oct 15, 2009, 4:51:41 AM10/15/09
to sysml...@googlegroups.com
Hello Cris,
I would like to have your opinion about the lack of complete Instance semantics in SysML.
Regards,
Dragos DOBRE
Doctorant - Nancy Université - Université Henri Poincaré
Centre de Recherche en Automatique de Nancy - CRAN
Faculté des Sciences, BP 70239
54506 Vandoeuvre-lès-Nancy
I would like to have your opinion about the lack of complete Instance semantics in SysML.
Regards,
Dragos DOBRE
Doctorant - Nancy Université - Université Henri Poincaré
Centre de Recherche en Automatique de Nancy - CRAN
Faculté des Sciences, BP 70239
54506 Vandoeuvre-lès-Nancy
Paul Ebert
Oct 16, 2009, 8:39:22 AM10/16/09
to sysml...@googlegroups.com
Thanks for the response, Chris.
I haven't learned how to define stereotypes in EA yet, so I think I'm currently stuck with deployment diagrams. I wish I could find a good training class to attend!
I'm not sure what's going on. I recall seeing the Paste Element dialog with the functionality you describe, but it is not appearing now when I drag and drop and element. I've tried it with a device and a block in my deployment diagram and a block in a block definition diagram. Do you have any idea why I might not be getting this?
Paul
Pete Kirkham
Oct 17, 2009, 7:20:44 AM10/17/09
to sysml...@googlegroups.com
For simple use, you just type the name for a new stereotype in the
"Stereotype" box on the connector properties dialog
<http://www.sparxsystems.com/uml_tool_guide/modeling_with_uml/connectiondetails.html>.
EA has extra features for custom stereotypes and for profiles, but if
all you want is to say X - «deployment» -> Y, that should suffice.
2009/10/16 Paul Ebert <a2e...@gmail.com>:
"Stereotype" box on the connector properties dialog
<http://www.sparxsystems.com/uml_tool_guide/modeling_with_uml/connectiondetails.html>.
EA has extra features for custom stereotypes and for profiles, but if
all you want is to say X - «deployment» -> Y, that should suffice.
2009/10/16 Paul Ebert <a2e...@gmail.com>:
edi...@sysmlforum.com
Oct 20, 2009, 2:05:16 AM10/20/09
to sysml...@googlegroups.com, umlf...@googlegroups.com
Gentle Modelers,
> I would like to have your opinion about the lack of complete Instance semantics in SysML.
This critical design flaw is described in the SysML FAQ
(http://www.sysmlforum.com/FAQ.htm) as follows:
--------------------------------------------------
...
SPECIFIC ISSUES:
- Instance syntax and semantics are lacking.
Since SysML does not reuse UML Instance diagrams and its Instance
construct, it does not support Instance syntax and semantics, which are
required for full simulation and execution capabilities. Stated
otherwise, SysML does not support UML1's Classifier-Instance dichotomy,
nor does it support UML2's Classifier-Part-Instance trichotomy, where
Parts may be considered to be "prototypical instances." Consequently,
while it is possible to define Parts as prototypical instances of Blocks
in SysML, there is no straightforward way to define Block instances with
slot values as required for full simulation and execution capabilities.
This is part of the reason that the Parametric diagrams specified in
SysML are incomplete, and explains why tool vendors must kludge this
capability in an ad hoc manner.
Recommendations: Add Instances and Instance diagrams to SysML and
explain how instance slot values work with Parametric diagrams.
...
--------------------------------------------------
If you are interested in learning more about other design flaws of SysML
1.x you may want to check out the SysML FAQ, which describes various
problems and includes recommendations to fix them.
/Cris
__________________________________________________
Cris Kobryn
Editor, SysML Forum
mailto:edi...@SysMLforum.com
www.SysMLforum.com
> -------- Original Message --------
> I would like to have your opinion about the lack of complete Instance semantics in SysML.
This critical design flaw is described in the SysML FAQ
(http://www.sysmlforum.com/FAQ.htm) as follows:
--------------------------------------------------
...
SPECIFIC ISSUES:
- Instance syntax and semantics are lacking.
Since SysML does not reuse UML Instance diagrams and its Instance
construct, it does not support Instance syntax and semantics, which are
required for full simulation and execution capabilities. Stated
otherwise, SysML does not support UML1's Classifier-Instance dichotomy,
nor does it support UML2's Classifier-Part-Instance trichotomy, where
Parts may be considered to be "prototypical instances." Consequently,
while it is possible to define Parts as prototypical instances of Blocks
in SysML, there is no straightforward way to define Block instances with
slot values as required for full simulation and execution capabilities.
This is part of the reason that the Parametric diagrams specified in
SysML are incomplete, and explains why tool vendors must kludge this
capability in an ad hoc manner.
Recommendations: Add Instances and Instance diagrams to SysML and
explain how instance slot values work with Parametric diagrams.
...
--------------------------------------------------
If you are interested in learning more about other design flaws of SysML
1.x you may want to check out the SysML FAQ, which describes various
problems and includes recommendations to fix them.
/Cris
__________________________________________________
Cris Kobryn
Editor, SysML Forum
mailto:edi...@SysMLforum.com
www.SysMLforum.com
> -------- Original Message --------
> Subject: [SysML Forum] Lack of complete Instance semantics in SysML
> From: "Dragos DOBRE" <dobre....@gmail.com>
> Date: Thu, October 15, 2009 1:51 am
> To: <sysml...@googlegroups.com>
>
>
> Hello Cris,
>
> I would like to have your opinion about the lack of complete Instance semantics in SysML.
>
> Regards,
>
> Dragos DOBRE
> Doctorant - Nancy Université - Université Henri Poincaré
> Centre de Recherche en Automatique de Nancy - CRAN
> Faculté des Sciences, BP 70239
> 54506 Vandoeuvre-lès-Nancy
>
>
>
> -----Original Message-----
> From: sysml...@googlegroups.com [mailto:sysml...@googlegroups.com] On Behalf Of edi...@SysMLforum.com
> Sent: jeudi 15 octobre 2009 02:36
> To: sysml...@googlegroups.com
> Cc: UMLf...@googlegroups.com
> From: "Dragos DOBRE" <dobre....@gmail.com>
> Date: Thu, October 15, 2009 1:51 am
> To: <sysml...@googlegroups.com>
>
>
> Hello Cris,
>
> I would like to have your opinion about the lack of complete Instance semantics in SysML.
>
> Regards,
>
> Dragos DOBRE
> Doctorant - Nancy Université - Université Henri Poincaré
> Centre de Recherche en Automatique de Nancy - CRAN
> Faculté des Sciences, BP 70239
> 54506 Vandoeuvre-lès-Nancy
>
>
>
> -----Original Message-----
> From: sysml...@googlegroups.com [mailto:sysml...@googlegroups.com] On Behalf Of edi...@SysMLforum.com
> Sent: jeudi 15 octobre 2009 02:36
> To: sysml...@googlegroups.com
> Cc: UMLf...@googlegroups.com
nsowatsk
Oct 19, 2009, 9:10:02 AM10/19/09
to sysml...@googlegroups.com, edi...@sysmlforum.com
Hi Cris
Did you send a follow up on the details of the instance semantics in SysML?
Many thanks
Nathan
Did you send a follow up on the details of the instance semantics in SysML?
Many thanks
Nathan
Ken Lloyd
Oct 20, 2009, 8:40:20 PM10/20/09
to umlf...@googlegroups.com, sysml...@googlegroups.com
Many SysML models we get confuse the map with the terrain.
Specifically, there are many instance models, as well as context instances
that need be considered in our modeling, simulation and visualization work.
It seems there are very few of us doing agent based mod/sim/vis upon
temporally extended SysML input models, however. Perhaps SysML is evolving
into a more primitive language for simple, static, abstract systems,
exclusively.
============================
Kenneth A. Lloyd
CEO - Director of Systems Science
Watt Systems Technologies Inc.
Albuquerque, NM USA
kenneth.lloyd[at]wattsys.com
kenneth.lloyd[at]incose.org
kenneth.lloyd[at]nmug.net
www.wattsys.com
http://www.linkedin.com/pub/kenneth-lloyd/7/9a/824
http://kenscomplex.blogspot.com/
This e-mail is covered by the Electronic Communications Privacy Act, 18
U.S.C. 2510-2521
and is intended only for the addressee named above. It may contain
privileged or confidential information.
If you are not the addressee you must not copy, distribute, disclose or use
any of the information in it.
If you have received it in error please delete it and immediately notify the
sender.
Specifically, there are many instance models, as well as context instances
that need be considered in our modeling, simulation and visualization work.
It seems there are very few of us doing agent based mod/sim/vis upon
temporally extended SysML input models, however. Perhaps SysML is evolving
into a more primitive language for simple, static, abstract systems,
exclusively.
============================
Kenneth A. Lloyd
CEO - Director of Systems Science
Watt Systems Technologies Inc.
Albuquerque, NM USA
kenneth.lloyd[at]wattsys.com
kenneth.lloyd[at]incose.org
kenneth.lloyd[at]nmug.net
www.wattsys.com
http://www.linkedin.com/pub/kenneth-lloyd/7/9a/824
http://kenscomplex.blogspot.com/
This e-mail is covered by the Electronic Communications Privacy Act, 18
U.S.C. 2510-2521
and is intended only for the addressee named above. It may contain
privileged or confidential information.
If you are not the addressee you must not copy, distribute, disclose or use
any of the information in it.
If you have received it in error please delete it and immediately notify the
sender.
ebe...@welchallyn.com
Oct 21, 2009, 7:53:47 AM10/21/09
to sysml...@googlegroups.com
Ken - I certainly hope SysML is not evolving into a more primitive language (of any type). I am rather new to this (I have a bit more experience with UML in software designs). I'm glad that this forum is starting to be more active as it is the best opportunity for me to learn (beyond the available books, which are good but only go so far).
Could you please elaborate on what agent based modeling, simulation, and visualization entails? And, in this context, what would temporarily extended SysML input models, entail?
Thanks,
Paul Ebert
Requirements Analyst
Welch Allyn, Inc.
4619 Jordan Rd.
Skaneateles Falls, NY 13153
315-554-5902
| "Ken Lloyd" <kal...@wattsys.com>
Sent by: sysml...@googlegroups.com 10/20/2009 08:40 PM
|
|
Russell Peak - GIT
Oct 22, 2009, 9:23:11 AM10/22/09
to sysml...@googlegroups.com
In response to the
subject thread regarding SysML and instances:
Instances are useful
(and I would say necessary) for engineering simulation and analysis
models. In my research lab at Georgia Tech we showed early on how to
execute SysML parametrics models that contain instances. InterCAX LLC has
commercialized that technology in a practical form, releasing the first such
product as ParaMagic for MagicDraw in Jul 2008 (with others in the works for
other SysML authoring tools).
Here are a few
related resources:
Though technically not part of SysML 1.0
or 1.1, we are able to define Block instances with slot values in several SysML
tools and thus achieve a workable practical solution today.
Recognizing the need
to support instances explicitly, the OMG SysML Revision Task
Force (RTF) has proposed the addition of instance notation to SysML
1.2, which has been submitted to the OMG for approval. See the entry for OMG
Issue Number 12277 "SysML needs instance specs" in the following document (which
you can access now if you are an OMG member, or you can wait for the SysML 1.2
spec release):
- Report of the
SysML Revision Task Force 1.2 to the OMG Platform Technical Committee (17 August
2009), OMG document ptc/09-08-13.
Hope this
helps,
Russell
OMG SysML RTF
representative for Georgia Tech
Russell S. Peak, PhD
Senior Researcher
Director
Modeling & Simulation Lab
http://www.msl.gatech.edu/
Senior Researcher
Director
Modeling & Simulation Lab
Associate Director
Product & Systems Lifecycle Management Center
http://www.pslm.gatech.edu/
Georgia Institute of Technology
813 Ferst Drive, MARC 373
Atlanta, Georgia 30332-0560 USA
voice +1-404-894-7572
Russel...@gatech.edu
]
On Behalf Of edi...@SysMLforum.com
Subject: [SysML Forum] Re: Lack of complete
Instance semantics in SysML
...
This critical design flaw is described in the SysML FAQ
(
...
This critical design flaw is described in the SysML FAQ
(
Laurent L Balmelli
Oct 20, 2009, 11:49:18 PM10/20/09
to sysml...@googlegroups.com, edi...@sysmlforum.com, sysml...@googlegroups.com
I also would be interested to know more about why this is a huge "design flaw". Can you please elaborate Cris?
The assertion in this thread that "you cannot assign value to constraint blocks because there is not instance semantics" is actually not correct.
In this case, SysML replaces the need for instances by the concept of Context-Specific Properties. When this is supported by the tool environment, you can assign values to the parameters in constraint properties created from the constraint block that are specific (i..e local) to its usage. This is much simpler that the concept of creating instances and provides the same benefits. There always has been an ambiguity in UML between the concept of a role of a classifier and an instance. SysML provides a nice middle ground to it. IBM has an implementation that will be part of a future tool release, but that we already provide it as a service to our customers, in particular in the scope of parametric models simulation.
There is certainly applications that make good usage of instances, especially in embedded systems design, but I have not seen so far in this thread an example that was not covered by the actual SysML specification.
Please share your examples, that would be very interesting!
----
Laurent Balmelli, Ph.D (春芽利 楼蘭）
Manager, IBM's SysML Representative
Systems and Product Lifecycle Research and Development
Rational Development & Services, Yamato Software Lab
1623-14, Shimotsuruma, Yamato-shi, Kanagawa-ken
242-8502, Japan
Phone: +81 46 215 4868, Cell +81 80 6597 0578
| nsowatsk <nsow...@cisco.com>
Sent by: sysml...@googlegroups.com 2009/10/19 22:10
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