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Subject: RE: [ebxml-cppa-negot] NDD Schema and Sample NDD instance documen t
(SEE PREVIOUS DISCUSSION QUOTED DIRECTLY BELOW.) This one probably requires direct discussion on the conference call but let me try another iteration. I was not thinking that the combined NDD would separately preserve the information about each Party's requirements, which I assume is what is meant by "the current schema does not allow this". I meant that the NDD would simply be a composite of the two sets of requirements that is acceptable to both parties as a starting point in negotiation. However, the composite is not like an inclusive OR (which I think I said in error). It is more like an intersection. If Party A is composing the NDD of the CPA template, Party A should exclude from the new NDD anything that Party A understands (from Party B's NDD) is unacceptable to Party B. So, for an enumeration, the new NDD should include only those choices that are common to both of the original NDDs. For a range of values, Party A should put in the new NDD only the common range. If, for some value, Party A had specified 1-9 and Party B had specified 3-12, the new NDD should specify 3-9. The intersection process may identify items with no common ground, making successful negotiation unlikely. One interesting question is, would it make sense for Party A to include items in the new NDD that were not in Party B's original NDD. The answer is "no" since Party B did not intend to negotiate on the items that it did not put in its original NDD. For those items that were not in Party B's initial NDD, Party A must either accept what is in Party B's NDD or recognize that there is an irreconcilable conflict. Note that it is not really mandatory for Party A to take Party B's NDD into account in composing the CPA template NDD since incompatibilities will anyway be removed during the exchange of counter offers. However, taking Party B's NDD into account will speed up convergence (or recognition of fatal incompatibilities)and reduce the possibilities of unnecessary rejects. In other words, composing a CPA template and combined NDD before starting negotiation simplifies the negotiation process by: - Removing subjects from negotiation that can be handled by simple matching. - Quickly recognizing the existence of fatal incompatibilities. (For fatal incompatibilies, the specification should recommend a phone call.) Regards, Marty PREVIOUS DISCUSSION: MWS: I don't think so. The combined NDD would refer only to the CPA template. <Kartha> I agree that the document pointed to by the NDD is only the CPA template. What I meant was that there should be elements in the NDD that correspond to negotiability requirements of both parties. And I believe that the current schema does not allow this. </Kartha> For instance, if party A wants to have the cardinality of an element betwen 1 and 4 (with preference for lower cardinalities) and party B wants to have the cardinality of that element between 2 and 3 (with preference for the higher cardinalities), it seems that both these should be represented in the initial NDD_1_A_B. Is this the way you were thinking about it, Marty? MWS: Not exactly. I was assuming that Party A would compose a single NDD that would encompass both parties' requirements to the extent that the other party's requirements are acceptable to party A. So, for example, if (in the example above), Party A would state the cardinality as 1-4 and then they would negotiate. <Kartha> Yes, but the information about the preferences is now lost (according to the current schema). </Kartha> ************************************************************************************* Martin W. Sachs IBM T. J. Watson Research Center P. O. B. 704 Yorktown Hts, NY 10598 914-784-7287; IBM tie line 863-7287 Notes address: Martin W Sachs/Watson/IBM Internet address: mwsachs @ us.ibm.com ************************************************************************************* "Kartha, Neelakantan" To: Martin W Sachs/Watson/IBM@IBMUS <N_Kartha@stercom cc: ebxml-cppa-negot@lists.oasis-open.org m.com> Subject: RE: [ebxml-cppa-negot] NDD Schema and Sample NDD instance documen t 09/30/2002 03:25 PM Marty, Thanks for your quick response. I have added my own comments, labeled <Kartha>. Everyone else: Please review and comment. Please note that I am pretty agnostic about either approach---my main interest is that the proposed schema caters to the approach that we choose, whatever that may be. Best, Kartha -----Original Message----- From: Martin W Sachs [mailto:mwsachs@us.ibm.com] Sent: Monday, September 30, 2002 1:57 PM To: Kartha, Neelakantan Cc: ebxml-cppa-negot@lists.oasis-open.org Subject: RE: [ebxml-cppa-negot] NDD Schema and Sample NDD instance documen t Kartha, Please see my replies below, labelled MWS:. It is important that everyone review and comment. Regards, Marty **************************************************************************** ********* Martin W. Sachs IBM T. J. Watson Research Center P. O. B. 704 Yorktown Hts, NY 10598 914-784-7287; IBM tie line 863-7287 Notes address: Martin W Sachs/Watson/IBM Internet address: mwsachs @ us.ibm.com **************************************************************************** ********* "Kartha, Neelakantan" To: Martin W Sachs/Watson/IBM@IBMUS <N_Kartha@stercom cc: ebxml-cppa-negot@lists.oasis-open.org m.com> Subject: RE: [ebxml-cppa-negot] NDD Schema and Sample NDD instance documen t 09/30/2002 12:33 PM Marty, Thank you for your remarks and your clarification to my comments. Here are some follow up remarks in response to your comments. 1. It seems that there are two related, although slightly different approaches now on the table. Let me first describe them. To start with, Party A has CPP_A and and NDD_A that points to CPP_A. Party B has CPP_B and NDD_B that points to CPP_B. MWS: One immediate problem is that the CPPA specification permits publishing CPA template instead of a CPP. I believe that this means that we would have to provide "Approach that Marty proposed" even if we agree to include Kartha's approach. <Kartha> Note that Steps 2-4 of "Kartha's approach" can cater to this case, with the caveat that the restriction proposed in Step 2, namely that "NDD1_A only points to the CPA specific elements in the CPA template" need to be removed if we are going to negotiate on elements of the CPP also. </Kartha> Approach I proposed: 1. Party A and Party B negotiate on elements that are in the CPP and come to an agreement on them. NDD_A and NDD_B are used during this process. MWS: CPP-A and CPP-B also have to be used in this process. <Kartha> Sure </Kartha> MWS: One possible problem here is that because there is no CPA template at this stage, everything that is negotiable in both CPPs have to be considered during this part of the negotiation process. Composing a CPA template first mechanically resolves all negotiable items that can be resolved by simple matching between the two CPPs and extracting the commonalities. See the discussion in the CPA composition appendix of the CPPA spec. 2. One of the parties (say party A) now makes a CPA template that contains the agreed upon values produced in step 1, as well as elements that are specific to the CPA (such as start, end etc.). Party A also produces an NDD1_A, that points to the CPA template. Note that NDD1_A does *not* refer to the elements of the CPP, since they already have been negotiated and agreed upon. NDD1_A only points to the CPA specific elements in the CPA template. Note however that the negotiability requirements that may be put in NDD1_A might depend on the first negotiation. 3. Consequently Party B also produces a similar NDD1_B template. MWS: Rather than working with two separate NDDs at this stage, I think it would be easier to produce a single NDD that refers to the draft CPA template and incorporates both parties' requirments on the CPA-only elements. The process of composing that combined NDD would detect any incompatibilities. 4. Party A and B negotiate on the elemtns that are in the CPA template and come to an agreement on them. NDD1_A and NDD1_B are used in this process. Approach that Marty proposed: 1. Party A composes a preliminary CPA template using CPP_A, CPP_B, NDD_A and NDD_B. In this CPA template, party A also inserts any CPA specific element like start, end. 2. Party A now produces a new NDD (call it NDD_1_A_B) that expresses its own and Party B's negotiability requirements. 3. A and B then negotiate and come to agreement using NDD_1_A_B A few remarks and questions: 1. A simple implementation of my approach can assume that that Steps 1 and Step 4 can be negotiated independent of each other. If we take that approach, the information in NDD1_A and NDD1_B can be made available at step 1 itself by each of them pointing to some standard CPA (such as the one available with the spec). Note that NDD1_A and NDD1_B can point only to CPA specific elements. 2. If as in Marty's approach an NDD (such as NDD_1_A_B) needs to refer to its own and the other parties negotiability requirements, the current schema needs to change so as to enable it to have a pointer to negotiability requirements of both parties. MWS: I don't think so. The combined NDD would refer only to the CPA template. <Kartha> I agree that the document pointed to by the NDD is only the CPA template. What I meant was that there should be elements in the NDD that correspond to negotiability requirements of both parties. And I believe that the current schema does not allow this. </Kartha> For instance, if party A wants to have the cardinality of an element betwen 1 and 4 (with preference for lower cardinalities) and party B wants to have the cardinality of that element between 2 and 3 (with preference for the higher cardinalities), it seems that both these should be represented in the initial NDD_1_A_B. Is this the way you were thinking about it, Marty? MWS: Not exactly. I was assuming that Party A would compose a single NDD that would encompass both parties' requirements to the extent that the other party's requirements are acceptable to party A. So, for example, if (in the example above), Party A would state the cardinality as 1-4 and then they would negotiate. <Kartha> Yes, but the information about the preferences is now lost (according to the current schema). </Kartha> Or, Party A could state an enumeration as the inclusive OR of both parties' requirements on that enumeration. Of course, since Party A is making the initial offer, Party A would exclude from the NDD any constraints that are unacceptable to Party A. MWS: The approach that I suggested gives the party making the initial offer has some advantage over the other party, which could be good or bad. The good part is that by initially filtering out the unacceptable parts of Party B's requirements, the negotiation may proceed more rapidly. This is in addition to the advantage that the CPA template composition process converges all negotiable items that can be resolved by simple matching. MWS: I believe that "Marty's approach" is already implicit in some aspects of the work that has been done on the BPSS and negotiation messages, so it will be important to discuss and resolve the differences between the too approaches fairly quickly. <Kartha> Maybe this is something we can discuss at the next conference call. I certainly agree that it is important to resolve the differences quickly so that we can proceed. </Kartha> Best, Kartha -----Original Message----- From: Martin W Sachs [mailto:mwsachs@us.ibm.com] Sent: Friday, September 27, 2002 5:29 PM To: Kartha, Neelakantan Cc: ebxml-cppa-negot@lists.oasis-open.org Subject: Re: [ebxml-cppa-negot] NDD Schema and Sample NDD instance document Kartha, Thank you very much for posting this material. It's a major step forward. I will study it next week. Regarding your question in the last paragraph: I believe that the thinking of the team has evolved to the following: The initial offer is always a CPA template and an NDD that references the CPA template. When the Party1 wants to make an offer to a Party2 that has published a CPP and an NDD, Party1 composes a CPA template from its and Party2's CPP. Party1 then composes a new NDD that references the CPA template and expresses its negotiability requirements. Party1 SHOULD include Party2's negotiability requirements (as expressed in its "CPP" NDD) in the new NDD. In other words Party1 SHOULD offer an NDD which is in some sense the inclusive OR of its "CPP" NDD and Party2's "CPP" NDD. It is also the responsibility of Party1 to insert into the CPA template the Start, End, and any other elements that are present in a CPA but not a CPP. I have said "Party1 SHOULD include Party2's negotiability requirements" because I don't think that a SHALL could be enforced. However, Party1 should expect that the negotiation will be much more likely to succeed if Party2's negotiability requirements are included in the offered NDD. The above is more or less what you say at the end, except that there is a single composite NDD (referencing the CPA template) rather than 2 separate NDDs in the initial offer. Regards, Marty **************************************************************************** ********* Martin W. Sachs IBM T. J. Watson Research Center P. O. B. 704 Yorktown Hts, NY 10598 914-784-7287; IBM tie line 863-7287 Notes address: Martin W Sachs/Watson/IBM Internet address: mwsachs @ us.ibm.com **************************************************************************** ********* "Kartha, Neelakantan" To: ebxml-cppa-negot@lists.oasis-open.org <N_Kartha@stercom cc: m.com> Subject: [ebxml-cppa-negot] NDD Schema and Sample NDD instance document 09/27/2002 05:51 PM Here is the promised NDD schema and a sample NDD instance document that conforms to this schema. The NDD instance document contains the first 15 or so elements in the spreadsheet that we filled earlier this year. The elements that are represented are different enough in their negotiability characteristics, so that the NDD schema captures all of the negotiation patterns I had identified earlier (in the document titled "Patterns in the negotiability of elements" that I had posted to the list in June 2002.) I have added comments on the NDD schema and instance document in the hopes that people will read them. Please send comments to me and to the list. The NDD schema is based on a skeleton schema that Dale Moberg had sent to me---however, note that I have made several changes and additions. What remains to be done: 1. Flesh out the NDD instance document more. Doing this might require additions/changes to the schema. However, in many (most?) cases, what is already in the schema should suffice. 2. Discuss whether the approach proposed here is appropriate/good enough. I noticed one issue while doing this work. There are some elements (such as Start/End etc.) that are present only in the CPA. Assuming that one starts out with two CPPs, the two initial NDDs point to these two CPPs. The question then is : how is the negotiation of these elements, present only in the CPA, to be done, since the NDD does not contain any references to them? An approach is: first finish the negotiation of the CPPs, form a preliminary CPA, with some arbitrary values for these elements. Then form two NDDs for this CPA, focusing on elements that are present only in the CPA. Comments? Best regards, Kartha <<NDD1.xsd>> <<sample_NDD.xml>> #### NDD1.xsd has been removed from this note on September 27 2002 by Martin W Sachs #### sample_NDD.xml has been removed from this note on September 27 2002 by Martin W Sachs
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