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Subject: Getting Back to Basics - How to describe Dates and Times and Events?
Section 8.1 Ground Rules for Constructing & Validating Core Components, of the ebXML Methodology: Core Components Discovery and Analysis (March 23, 2001) Version 1.02 specification, states "A core component is a basic building block for the creation of a semantically correct information exchange parcel. It is atomic in its fundamental construct. It contains only the essential information pieces necessary to describe the concept in a non-contextual manner." I think that's a good definition of a BASIC core component - the atomic building block of aggregate core components. Did we ever settle on Date and Time basic core components? And once we've done that, how do we make Dates and Times useful? It's not enough to just say something is a particular Date or Time (or even DateTime combination) - what event are we describing? We always pay lip-service to UN/EDIFACT, so why not look at how it describes events? In UN/EDIFACT, Events are described with the DTM (DATE/TIME/PERIOD) Segment, which basically gives the event or function, and the Date, Time or DateTime when the event occurs. You can see the DTM at http://www.unece.org/trade/untdid/d01a/trsd/trsddtm.htm. D.E. 2005 (Date or time or period function code qualifier) has a huge list of every possible event known to mankind in the area of trade and commerce. The DTM can be used a number of ways in a typical message, like the ORDERS Purchase order message; if you take a look at the ORDERS at http://www.unece.org/trade/untdid/d01a/trmd/orders_c.htm, and read Section 4.1: Segment clarification, you'll see that the DTM can be used in the front (header) of the message to describe events related to the entire message - e.g., The Date/Time of the message itself (when it was created), or the Requested Delivery date/time: the date you expect most or all of the junk you ordered to be delivered. Or the DTM can be used within a PO line item to override or augment the dates in the header - to say that this particular product has to be delivered 2 days before the rest of the order is expected. Or the DTM can be used to augment a reference (RFF) - e.g., to identify the date the Blanket PO was issued. The placement of the DTM segment, in addition to the function code qualifier, determines its "context." And only a few of the codes in D.E. 2005 will be applicable in a certain context (you could pick a dozen or so that have any real meaning in the ORDERS header). So how is all of this going to be done using ebXML core components? How do you model this? Where does context arise? Any examples? William J. Kammerer FORESIGHT Corp. 4950 Blazer Pkwy. Dublin, OH USA 43017-3305 +1 614 791-1600 Visit FORESIGHT Corp. at http://www.foresightcorp.com/ "accelerating time-to-trade"
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