The SGML Centre

The role of process-controlled components in

ebXML messagesMartin Bryan

CEN/ISSS Electronic Commerce Workshop working group on Defining

and Managing Semantics and Datatypes (DAMSAD)

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Structure of Presentation

What is the problem we need to solve? XML DTDs/Schemas Data Dictionaries Related standards initiatives

Why is context important to solving this problem?

How does ebXML use context?

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The Problem - Overview

DTDs define semantics for a sequence of elements that make up a message DTDs that cover wide ranges of data tend

to become very complicated (or non-specific) and difficult to manage

Data dictionaries provide a "flat view" of all data within a company Data is presumed to be used consistently

in all situations

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The Problem - DTDs

DTDs that allow everything and, therefore, control nothing<!ELEMENT shared-datatype(a?, b*, c?, d*, e?, f*)>

<!ELEMENT a (x|y|z)*>

Parameterized DTDs that allow complete user control<!ELEMENT shared-datatype (%p.x;)*>

<!ENTITY % p.x "a|b|c%x.extensions;">

<!ENTITY % x.extensions "">

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Do XML Schema Types help?

<complexType name="AbstractAddress" abstract="true"> <sequence> <element name="name" type="string"/> <element name="street" type="string"/> <element name="city" type="string"/> </sequence></complexType><complexType name="US-Address"> <complexContent> <extension base="AbstractAddress"> <element name="state" type="US-State"/> <element name="zip" type="positiveInteger"/> </extension> </complexContent></complexType>

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Creating Abstract Elements<element name="AbstractOrder" abstract="true">

<sequence> <element name="Partner" substitutionGroup="AbstractAddress">

<minOccurs value="2">

<maxOccurs value="10">

</element> <element name="Items" substitutionGroup="AbstractItems">

<minOccurs value="1">

<maxOccurs value="unbounded">

<element/> </sequence> <attribute name="orderDate" type="date"/></element>

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Using Abstract Elements <element name="PurchaseOrder">

<annotation> <documentation>Local Purchase Order</documentation></annotation><complexType>

<complexContent> <extension base="AbstractOrder"/> </complexContent></complexType>

</element>

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The Problem - Data Dictionaries Too little control - generic data types Name - without a context it is meaningless

Too much control - constrained data types AcknowledgementRecipientName - can't be

used in another context without renaming Confusing data type with data role (à la ISO

Basic Semantic Register) AcknowledgementRecipient.Name - name is

not a data type, it’s a use of a data type

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Mapping ISO 11179 view to XML

Representation

Properties

Concept/Class

Meaning

Element Name

Attribute Name/Embedded Element

Attribute Value/Element Content

Interpretation of Value

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UN/EDIFACT message structures

EDIFACT = Electronic Data Interchange for Administration, Commerce and Transport

EDIFACT messages are made up of reusable "segments"

Segments have a fixed sequence of "data elements"

Role of segments indicated by "qualifier" data elements

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Example of EDIFACT messageUNH+900576+ORDERS:D:93A:UN:EAN007'

BGM+220+H940568'

DTM+137:19940201:102'

NAD+BY+5412345000176::9'

NAD+SU+4012345000094::9'

LIN+1'

PIA+5_1857990455:IB'

IMD+F+BAU+:::Farell J G'

IMD+F+BTI+:::The Singapore Trip'

QTY+21:1'

PRI+XXX:7.99'

UNS+S'

CNT+2:2'

UNT+15+900576'

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Process Chains/Hierarchies

Manufacture Distribute Retail

Order Response Despatch Receipt Invoice Payment

Transport Booking

Container Movement

Collection Notification

Delivery Notification

Container Arrival

Su

bp

roce

sses

Process Chains

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How context affects information Some examples

Order/Item/Quantity[Units="Kilogram"]Despatch/Item/Quantity[Units="Kilogram"]Receipt/Item/Quantity/Received[Units="Kilogram"]

Invoice/Item/Quantity[Units="Kilogram"] Note how the initial context changes Note how the qualifier can change place Need to be able to identify whenever a

particular type of units applies to a quantity

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Basic processes for an Order* How is it to be distinguished? When was it issued? Who issued it? Who is to be executed by? Who else is to be informed? What is to be supplied? When and where is it to be delivered?

* Expressed as a set of questions that need to be answered in order to create an order

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Basic processes for Order Response How is it to be distinguished? When was it issued? Who issued it? What order does it refer to? Who is to be executed by? Who else is to be informed? What is to be supplied? When and where is it to be delivered?

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Basic processes for Despatch Note How is it to be distinguished? When was it issued? Who issued it? What order does it refer to? Who is to be executed by? Who else is to be informed? What is to be supplied? When and where is it to be delivered?

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Basic processes for Receipt How is it to be distinguished? When was it issued? Who issued it? What order does it refer to? Who delivered the goods? When and where were they delivered? What was received and accepted? What was rejected/not received?

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Basic processes for Invoices How is it to be distinguished? When was it issued? Who issued it? Who is it submitted to? What order does it refer to? What did the goods delivered cost? What tax needs to be paid on the goods? What is the total payment? Where is payment to be made?

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Basic processes for Payment Instructions How is it to be distinguished? When was it issued? Who issued it? Who is to receive the payment? Who else needs to be informed? What invoice does it refer to?

What did the goods delivered cost? What tax has been paid on the goods? What is the total payment?

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Conclusions from above Business messages are designed to

provide a set of answers to an agreed set of questions

The order in which the questions are answered is not relevant

Failure to answer one of the questions may invalidate the whole message

Not all parts of all questions need to be answered for a particular message

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Conclusions from conclusions - 1

Need to design reusable questions Answers may be omitted where not

relevant Need to be able to obtain answers

from different sources Often able to supply some answers from

previously answered questions Some questions need input from human or

"intelligent" system (i.e. bar code readers)

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Conclusions from conclusions - 2

The process and subprocesses in which information is collected provide a "parent" for the answer<Deliver> <Born>

<Date> <Date><Time> <Time><Address> <Address> <BuildingID> <Place> <Street> <Region> <Place> <Country> <PostalID>

<Region> <Country>

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Conclusions from conclusions - 3

Questions make natural parents <DeliverySpecification>

<WhenRequired> <Date> <Time> <WhereRequired> <Address> <BuildingID> <Street> <Place> <PostalID> <Region> <Country> <WhatIsRequired> <ProductIdentification> <QuantityRequired>

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ebXML

Brings together XML and EDI experts OASIS members for XML UN/EDIFACT for EDI Many other trade bodies for vertical

industries Looking to identify sharable processes

Core components for data Common business processes

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The ebXML committee structure

Requirements Technical Architecture Business Process/Core

Components Registry/Repository Transport Marketing

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Processes

Transport

Process Chain

Info.Entity

Info.Entity

Info.Entity

Components

Business Document

Business Process

Technical Architecture

Requirements

Methods

Registry and Repository

ebXML Group Linkages

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Overall ebXML BP Metamodel

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Message metamodelCore Component

Type Definition

BasicInformation Entity

AggregateInformation Entity

Datatype

Permitted Value

Permitted ValueMeaning

External List

Embedded Group

Type Use Rules

TypeConstraint

Functional SetAssemble

TypesContext Rules

ApplicationComponent

DatatypeConstraint

TypeExtension

Document Model

Context Constraints

Core Components

ApplicationRules

Aggregation Rules

Taxonomy

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ebXML Core Component Types

Core Component Type Definitions Basic Information Entity

Data Type Permitted Values/External Lists

o Permitted Value Meanings

Aggregate Information EntityEmbedded GroupAggregation Rules

Type Use Ruleso Type Constraint

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Context Control

Identify and assemble type definitions Identify subcomponents to be used Identify relevant context taxonomies Assign application dependent names

Apply context specific rules Identify relevant context taxonomies Define tests to be used to select rule Define extensions and restrictions to be

applied

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Assemble Types <Assemble Name=”PurchaseOrder”>

<CreateGroup Type=”sequence”> <CreateElement Type=”PartyType” id="Buyer"> <Name>Buyer</Name> <CreateGroup type="sequence"> <UseElement name="Name"/> <UseElement name="Address"> <UseElement name="StreetName"/> <UseElement name="City"/> <UseElement name="State"/> <UseElement name="ZIP"/> </UseElement> </CreateGroup> <Condition test="Region='UK'"> <Rename from=”address” to=”addressUK”/> <Rename from="address/State" to="County"/> <Rename from="address/ZIP" to="PostalCode"/> </Condition> </CreateGroup>

</Assemble>

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Condition Rules <Rule>

<Taxonomy context="Process" ref="http://www.ebxml.org/classes/CoreBP"/><Taxonomy context="Industry" ref="http://www.ebxml.org/classes/industry/aviation"/> <Condition Test="Process = 'Quote'"> <Condition Test="Industry = 'Automotive'"> <Action ApplyTo="QualifyingInfo"> <Add> <Field Name=”DrivingRecord” Type=”DrivingRecord”/> <Field Name=”CarDescription” Type=”CarDescription”/> <Field Name=”DrivingHabits” Type=”DrivingHabits”/> </Add> <Rename from="@Convictions" to="@DrivingConvictions"/> </Action> </Condition> . . .

</Rule>

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ebXML Registry Structure

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What have we learnt?

Information is dependent on context You need to know the context of a

message to be able to interpret its contents

Context is dependent on the processes involved

Therefore semantic definitions must also be dependent of processes using data elements

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Where to find more information

On ebXML www.ebxml.org

On European Electronic Commerce www.cenorm.be/isss/Workshop/ec

On standards for Electronic Commerce www.diffuse.org/standards.html

On background philosophies www.sgml.u-net.com