[step-manufacturing] Minutes of January 21st conference call

[Martin Hardwick]

Attendees
--------------
Martin Hardwick, STEP Tools, USA
Joe Fritz, STEP Tools, USA
Julie Huang, Sandvik Sweden
Bengt Olsson, Sandvik, Sweden
Mikael Hedlind, Scania, Sweden
Alain Brail, Airbus (retired), France
Christian Caillet, Datakit France
Bryan Dods, GE Power and Water, USA
Charles Gilman, GE Global Research, USA
David Odendahol, Boeing, USA
Sid Venkatesh, Boeing, USA
Robert Erickson, Pratt & Whitney, USA
Vincent Marchetti, Ameritech, USA
Ted Driggs, Okuma, USA
Tom Raun, Iscar, USA
Larry Maggiano, Mitutoyo, USA

We discussed a distributed machining scenario and how it should be 
supported within the STEP infrastructure. We agreed that the identity of 
two instances can be determined by their digital signatures. Therefore, 
the new version of the STEP file format should state that URI references 
shall be considered equal if they evaluate to the same http address, or 
if they reference a file with the same digital signature. Consequently, 
if a machining item has already been cached because it was previously 
sent in a multi-file ZIP, or if it was previously de-referenced from a 
different URI then a second transmission is unnecessary and redundant.

Some or all of the following information should be stored about a 
networked reference
1. A URL so that the file can be found using the http protocols
2. A GUID so that the file can be found using a catalog search
3. The digital signature check sum so that the system can determine if 
the file has been updated since it was last referenced.
4. A name so that an end user can recognize which file is being referenced.

This information can be distributed between the Reference section and 
the Schema population of the new standard.

Considerable resources are current being devoted to issues such as these 
as part of the Industrial Internet of Things (IIoT). The Magnet URI 
specification is seeking to implement similar functionality in a more 
general context. We need to verify that our proposal is compatible with 
the PLM systems widely used by the large industrial companies. The 
Digital Object Identifier (DOI) scheme is widely used to enable unique, 
location independent references to academic papers.
http://www.industrialinternetconsortium.org/
http://magnet-uri.sourceforge.net/
http://en.wikipedia.org/wiki/Digital_object_identifier

We discussed the representation of additive manufacturing process data 
within the STEP-NC framework. Care needs to be taken because there are 
many types of additive manufacturing processes and many of them are 
spatially independent. However, if the process data does vary by 
location then the similarities to machining data are quite strong and 
there should be value in capturing that data within the STEP framework 
because the process can then be shown in the context of the features and 
tolerances being manufactured at the process location.

A recording of this conference calls is on the web site at the address 
below:
ftp://www.steptools.com/private/CAM_exchange/Cycle_5/stepmanuf_telecon_20150121.wmv

The next conference call will be held on Wednesday February 4th.

Martin Hardwick
Team Leader ISO STEP-Manufacturing