Minutes of UBL TC meeting 17 August 2006 (1)

UBL TC MINUTES FOR THURSDAY MORNING 17 AUGUST 2006

Members attending the Montral meeting in person:

Jon Bosak (chair)

Mikkel Brun

Mavis Cournane

Mike Grimley

G. Ken Holman

Andy Schoka

Paul Thorpe

Observer attending in person:

Christian Lanng

Members attending by phone:

Tim McGrath (vice chair)

Peter Borresen

The phone line was open starting around 9 a.m.

Support package scheduling (carried over from Monday)

"UML and EF data models (pointers) (McGrath)"

ACTION: TM to upload the Enterprise Architect UML data

model; JB to link this from the UBL 2.0 index file and add a

subsection for this in the same section as the document

models.

TM: Is the EF model in sync with the final schemas,

including the changes that GKH handcrafted?

MC: We have confirmed with SW that these changes have been

incorporated in FX; see posting to the list.

[At this point PB joined the call, and in the subsequent

discussion of the use cases, we forgot to assign an action

item covering publication of the EF data model.]

"Danish use cases and example instances (Borresen)"

"Sample business rules expressed in schematron (Borresen)"

"Input Xforms (Borresen)"

PB: We will deliver a package containing sample documents,

scenario descriptions, schematron and XSL transformations,

and XForms when we give our presentation at the November TC

meeting in Singapore.

AGREED that these materials should go into the Support

Package as "Sample Implementation Guide from Denmark."

"Output stylesheets (maybe by reference) (Holman)"

GKH: HISC still dormant due to lack of resources; will not

have stylesheets done by November, but will have one for

Invoice demonstrating stylesheet generation.

Proposed customization methodology

GKH walked us through his proposal on "UBL 2.0 subsets,

extensions, versions, validation and interchange":

http://www.oasis-open.org/committees/document.php?document_id=18849

The xpath-based methodology developed for the UBL SBS turns out

to have a lot of uses.  The xpath file enumerates all xpath

addresses of all information items in a given document type,

thus allowing programs to see the hierarchy of elements;

schemas only show parent-child relationships, but xpath files

show ancestor descent relationships as well.  Given certain

other conditions (e.g., use of global types throughout), this

capability allows xpath files to be used to programatically

verify that a given schema defines a proper subset of another

schema -- most importantly for us, to guarantee that any

instance validating against a particular UBL subset schema will

also validate against the standard UBL schema for that document

type.  The proposal uses this capability to provide a set of

tools for verifying conformant UBL subsets.  The tools will be

made available from the Crane Softwrights site under some form

of non-assertion covenant.  Note that the methodology says

nothing about how a subset is created; it just provides an

automatable way to verify it for compliance.

Benefits of this approach include:

- Automates verification of subset compliance with standard

UBL schemas

- Allows the generation of XSLT files that can be used in the

second UBL validation phase to automatically strip out info

items defined by minor UBL versions later than the version

that a given implementation will support; this means, for

example, that the NES group can publish an "NES Subset

Filter" that will turn any UBL instance into an NES instance

- Provides a formalization for a shared "validation shell"

that can be specified in trading partner agreements.  In

support of this capability, GKH provides an enhanced version

of Schematron 1.5 that implements the ISO Schematron

"include" directive

- Removes any dependence on problematic XSD

extension/restriction mechanisms for doing customizations

- Can apply also to minor versioning (because the major

version is a subset of the later minor version)

Since this approach caters to the user need to have everything

possible defined using XSD schemas, UBL SBS 2 will be defined

using a set of actual subset schemas rather than just a set of

xpath files.

AGREED that "customized schema" is probably a better term than

"subset schema" because the customized schema can in fact

contain extensions.

AGREED that the proposed methodology is a significant

contribution and should be written up as our customization

methodology, to be published as a Committee Specification.

AGREED that the proposed methodology does not obviate the need

for a separate, later CS on customization guidelines, i.e.,

guidelines for how to actually create customizations.

AGREED that the methodology points toward a possible strategy

for minor versioning that we will discuss further after the

release of UBL 2.0.

Third public review

AGREED that we will perform a third public review to fix a

couple of problems discovered in the second public review.

AGREED to allow the PSC to determine the specific actions to be

taken to effect the necessary repairs.

AGREED to include a number of other changes previously

identified as candidates for revision in UBL 2.1.

AGREED to accept the offer of the Danish team to manage

production of the revised schemas.

AGREED on the following workflow:

- JB produces a detailed schedule of this review cycle ASAP

- UBL PSC decides the disposition of issues 11 and 15

- As soon as the PSC has disposed of 11 and 15, TM publishes

the PRD3 change log (including the implementation of a

number of other changes that would otherwise have been

deferred till 2.1)

- PB changes the spreadsheets per the change log and generates

a new set of schemas

- In parallel, MG manually revises the PRD2 schemas per the

change log to produce a parallel set of schemas

- PT converts both sets of schemas to ASN.1 and performs a

diff for Q/A purposes

- When we're satisfied that the schemas have been correctly

revised, we put the resulting PRD3 to a vote and move to

public review

AGREED that we will bundle formal approval of the changes into

the vote on the PRD3 Committee Draft.

Jon Bosak
Chair, OASIS UBL TC