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Subject: RE: [plcs-dex] What is a DEX
All I am trying to say (badly) is that we use the term DEX to mean two things and that we use the term interchangeably. We use it to mean an information model We use it to mean data that is exchanged. I propose that for the former we say "PLCS DEX" and for the latter "DEX data sets" to avoid confusion. Regards Rob > -----Original Message----- > From: Per-Åke Ling [mailto:per-ake.ling@eurostep.com] > Sent: 31 August 2005 18:04 > To: rob.bodington@eurostep.com > Cc: 'Barker, Sean (UK)'; peter.bergstrom@eurostep.com; 'DEXS-PLCS-OASIS > (E-mail)' > Subject: Re: [plcs-dex] What is a DEX > > Hmm, the last sentence in [2] below "...the DEX information model" is a > subset of ISO 10303-239 as in [1]... I am not sure I understand the > distinction except that "DEX" can mean either a (subset) model or > instance data according that same model, which is essentially [2]. Note > that [1] is "just" a model while [2] is model and data... > > So, DEX means both "a model" and "instance data as exchanged" according > to your unconfused suggestion. ? > > Regards, > Per-Åke > > Rob Bodington wrote: > > Mats Nilsson raised the question before "What is a DEX" and pointed out > that > > we use the term DEX to mean two different things. > > > > 1) A DEX identifies a subset of the ISO 10303-239 (PLCS) information > model > > required to support a set of identified arrows and activities in the ISO > > 10303-239 Activity model. > > > > 2) A DEX is also used to refer to a package of data that is exchanged. > I.e. > > the actual data that is exchanged in accordance with the DEX information > > model. > > > > To avoid confusion, I propose that we refer to the second use of DEX as > "DEX > > data sets". > > > > Regards > > Rob > > > > > > > >>-----Original Message----- > >>From: Barker, Sean (UK) [mailto:sean.barker@baesystems.com] > >>Sent: 30 August 2005 09:34 > >>To: peter.bergstrom@eurostep.com; DEXS-PLCS-OASIS (E-mail) > >>Subject: RE: [plcs-dex] What is a DEX > >> > >> > >>Peter, > >> > >> Your summary is, for the most part, correct. My note was > >>essentially about a detail of the definition of a DEX, namely, whether > >>Message is part of a DEX, or whether it is external to a DEX. > >> It is also a clarification of the statement "a File will contain > >>one DEX". Since a DEX is a specification, the question was whether this > >>statement meant it conformed to one DEX specification, with multiple > >>instantiations, or whether it meant a single instantiation. Restriction > >>of the number of instantiations is, therefore, a matter of exchange > >>agreement (business rule). > >> The term Task Set arises from the AAM lifecycle stage, in which > >>the DEX supports the evolution of the support solution. One element of > >>this is the contracting for the set of tasks applicable to an equipment > >>and its sub-equipments. The function of task set is mainly to control > >>contracting for the set of tasks, as well as interchange the task > >>descriptions. It is this contracting/lifecycle control aspect of Task > >>Set that has been put out of scope. > >> I hope this clarifies. > >> > >> > >> > >>Sean Barker > >>0117 302 8184 > >> > >>-----Original Message----- > >>From: Peter Bergstrom [mailto:peter.bergstrom@eurostep.com] > >> > >>Sent: 27 August 2005 08:27 > >>To: Barker, Sean (UK); DEXS-PLCS-OASIS (E-mail) > >>Subject: RE: [plcs-dex] What is a DEX > >> > >> *** WARNING *** > >> > >>This mail has originated outside your organization, either from an > >>external partner or the Global Internet. > >> > >> Keep this in mind if you answer this message. > >> > >> > >>I'm sorry, but I don't understand. I probably misunderstood something > >>very basic here, so I better explain my view and let wiser men (and > >>women) tell me what I didn't understand... > >> > >>I though the DEX was a specification for an exchange file. In my mind, > >>the DEX is standardized and fixed through OASIS, you would never send > >>'it'. You would send and exchange file _conforming_ to the DEX. > >> > >>DEX3 would in my mind specify how tasks have to be structured/encoded to > >>be transmitted accorded to DEX3 and PLCS. I thought DEX3 should not say > >>you cannot send more than one task at the time (that, too me, would be > >>quite rediculous). It would specify the structure/format for instances > >>according to the Task(_method)-entity and related entities. > >> > >>If someone would want to limit the exchange file to say 'just one task > >>per file', they would do so in the exchange agreement, I would say, or > >>possibly in the Business concept, but it is not part of the DEX to make > >>such limitations. > >> > >>Regarding the name 'Task-set', I have always wondered why the 'set' was > >>there. The DEX shouldn't either specify you have to send a set of tasks. > >>In my mind, an exchange file conforming to a future DEX3 specification > >>could contain 1 or many tasks. I would actually prefer to have the name > >>be 'task', not 'task set'. > >> > >>If I have misunderstood the entire issue with your email here, please > >>tell me so and don't waste more time on this. If I haven't, I'm > >>worried... > >> > >> > >>Peter > >>-- > >>Peter Bergstrom office: +46-8 200 440 > >>Eurostep AB mobile: +46-708 111 966 > >>Vasagatan 38 fax: +46-708 111 965 > >>111 20 Stockholm > >>Sweden > >> > >>-----Original Message----- > >>From: Barker, Sean (UK) [mailto:sean.barker@baesystems.com] > >>Sent: den 26 augusti 2005 16:17 > >>To: DEXS-PLCS-OASIS (E-mail) > >>Subject: [plcs-dex] What is a DEX > >> > >> > >> > >>At DEX 3 meeting, we had a discussion arising from the definition of a > >>DEX in the context of Task-list. The discussion is summarized in the > >>attached figure. Essentially the question is whether the message entity > >>is part of the DEX, but the argument goes as follows: > >> > >>1) A DEX is a design, rather than a physical file (DEX as Realized). > >> > >>2) Create temporary term "DEX content item", meaning everything but the > >>message. > >> > >>3) An exchange consists of a message AND [[Exactly one DEX content item] > >>OR > >> [Many DEX > >>content item]] > >> > >>The user requirement (Norwegian Frigate) was for many DEX content items. > >> > >>4) A DEX is either [The DEX content items] OR [The message entity AND > >>the DEX content items] > >> > >>The preferred solution was [Message AND DEX content items] (Bottom > >>right, in red). > >> > >>In the case of DEX 3, the content item is a Task, and > >>Message.Content_item[i] points to each Task. > >>No DEX can contain the content of any other DEX. > >> > >>5) Note: the various items in the DEX are independent of each other, and > >>the fact that they come as a collection is merely a convenience, for > >>example, to avoid having to manage too many files. Tool vendors have a > >>valid input at this point. The number of items per DEX may be restricted > >>by business rule. > >> > >>6) We can now delete the term "DEX content item", and say, say, DEX 3 > >>contains a message and several Task descriptions. > >> > >>Note: The users have decide to restrict the scope of DEX 3 to Task. This > >>is narrower than the original Task-set, wherein the Task-set would > >>define a collection for a specific purpose and provide any appropriate > >>meta-data. Discussions have been started about generalizing DEX 5 to > >>cove such a requirement. > >> > >>DO NOT SHOOT THE MESSENGER. > >> > >>Sean Barker > >>0117 302 8184 > >> > >> > >> > >>******************************************************************** > >>This email and any attachments are confidential to the intended > >>recipient and may also be privileged. If you are not the intended > >>recipient please delete it from your system and notify the sender. > >>You should not copy it or use it for any purpose nor disclose or > >>distribute its contents to any other person. > >>******************************************************************** > >> > >> > >> > >> > >>******************************************************************** > >>This email and any attachments are confidential to the intended > >>recipient and may also be privileged. If you are not the intended > >>recipient please delete it from your system and notify the sender. > >>You should not copy it or use it for any purpose nor disclose or > >>distribute its contents to any other person. > >>******************************************************************** > > > > > > > -- > ======================================================== > Per-Åke Ling email: per-ake.ling_AT_eurostep.com .~. > Eurostep AB mobile: +46 709 566 490 / v \ > Vasagatan 38 http://www.eurostep.com /( _ )\ > SE-111 20 Stockholm ^ ^
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