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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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