[wg11] Part 28 teleconferences

[Martin Hardwick]

At 11:39 AM 7/16/2004 -0400, Ed Barkmeyer wrote:
>Heidi L Preston wrote:
>
>> Here is a summary of what I have heard from the last few
>>days of exploder comments:
>>REQUIREMENT 1:
>>Consensus: We need a simple XML Schema derived from the EXPRESS model by
>>simple rules with no options.  It should eliminate restrictions and
>>features that make the XML Schema difficult for people to read and
>>difficult for tools to use.  This binding needs to be short, clear and
>>concise so that any errors in this specification can be rapidly determined
>>and eliminated.
>
>agree.
>
>>Open for discussion:
>>1.  The AP binding needs to follow the mainstream conventions for XML data
>>(no surprises to the end user).
>>2. The AP binding must have sufficient legibility/understandability to
>>allow the AP developers to add definitions to the schema that may come from
>>the AAM, ARM, mapping tables and AIM rules.
>>3. The AP binding must support conformance checking so that vendors and end
>>users can easily determine if an XML data set conforms to the AP.
>>4.  The AP binding should be at least as easy to implement as Part 21 and
>>should make STEP data easier to understand.
>
>In bullets 1-4, the term "AP binding" refers to the "simple XML Schema derived from the EXPRESS model by simple rules with no options", right?

Yes and no. The AP binding is targeted at the people who implement STEP
today. This is compatible with being simple but the emphasis is important
to T24 and PLCS. 


>In bullet 3, what is meant is:
>"The AP binding must permit EXPRESS-based conformance checking, so that ..."  (It may not have to do anything special to support it, but it must not do things that make EXPRESS-based conformance checking difficult.)

The primary requirement is that everyone should
be able to agree on what is correct and incorrect. This is
a constraint on the specification more than anything else. It must
be concise and easy to understand so that the implementors can quickly
agree on what is wrong in any failed data exchange and if there
is any error in the spec it can be quickly identified and fixed using
a SEDs.

What tools are used to help the implementors identify bad data does not
matter. If the spec is unambiguous tools will be implemented because
a market exists for the software.


>Also, I think we need a bullet 5:
>5.  The XML schema, and the conforming XML documents, should not *require* pre-processors, post-processors, or their exchange libraries to have any knowledge of EXPRESS.  They may use other documentation to understand the semantics of the exchange, and the corresponding rules and constraints.


This is poorly addressed by bullet #4. What I mean here is that those who currently
have AP implementations based on P21 should be able to rapidly convert to
the AP Binding specification and that they should be able to do so without being
required to purchase or otherwise obtain any special tooling for the "fancy"
pre-processing, post-processing etc.

Thanks for the feedback. I will have a go at re-phrasing. As per the mandate
given to T24 at the Bath meeting we will be sending out a Strawman binding
towards the end of the day that meets these requirements so that we can talk
about it during the telecon on Monday.

Martin

<snip>

>Thanks,
>-Ed
>
>-- 
>Edward J. Barkmeyer                        Email: edbark at nist.gov
>National Institute of Standards & Technology
>Manufacturing Systems Integration Division
>100 Bureau Drive, Stop 8264                Tel: +1 301-975-3528
>Gaithersburg, MD 20899-8264                FAX: +1 301-975-4694
>
>"The opinions expressed above do not reflect consensus of NIST,
> and have not been reviewed by any Government authority."
>
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