Position Paper

Virtual Enterprises require OMA/WWW integration

Craig Thompson

NIIIP Project Office

National Industrial Information Infrastructure Protocols Consortium

1055 Washington Blvd. 10th Floor, Stamford CT 06901

tel: 214 379 3320, email: thompson@objs.com

About the NIIIP Consortium. The National Industrial Information Infrastructure Protocols Consortium (NIIIP) is developing technology to enable industrial virtual enterprises (VEs). An industrial VE is a temporary consortium of independent member companies which come together to quickly exploit fast-changing worldwide product manufacturing opportunities. Virtual Enterprises assemble themselves based on cost effectiveness and product uniqueness without regard for organization size, geographic location, computing environments, technologies deployed, or processes implemented. Virtual Enterprise companies share costs, skills, and core competencies which collectively enable them to access global markets with world class solutions that could not be provided individually.

In order to enable VEs, NIIIP is developing protocols and a reference implementation that ties together several emerging infrastructure technologies: Internet, web, OMG object technology, workflow, KBMS, rules, agents, and STEP product data. Rather than standardize protocols itself, NIIIP works through memberships in standards organizations, principally OMG (Internet SIG, Manufacturing TF), WfMC, and STEP. Much of the NIIIP work involves "harmonizing" the many sets of existing protocols, and then doing pilot projects to prove out the approach. NIIIP has ongoing work in many of the areas the W3C-OMG workshop is focused on. Three are described here.

NIIIP Desktop. The purpose of the NIIIP Desktop is to provide an interface for VE clients to create and manage VE tasks and sessions. Tasks, tools, and data are modeled as OMG IDL objects. The modeled entities are consistent with CAD Framework Initiative and Workflow Management Coalition protocols. One of our experiments involving web-object integration was to use a WWW browser as a VE client interface. In the initial demonstration, html forms were used by a VE client to render and browse NIIIP Desktop objects. User selected method calls were sent to the web server and a CGI binary program used to interpret the message and make an IDL call. Drawbacks of this approach include that it required the user to request refreshes and that the CGI program was started for each selected method call. We are now working on a follow on variant in which a Java applet on the web client calls the server and Java on the server calls C++ ORB clients.

VE Repository Browser. The STEP community is standardizing product data descriptions. As part of its NIIIP effort, STEP Tools, Inc.developed a web-based VE repository browser for STEP data.The repository lets web clients browse an AP203 data set and download parts of that data set into their CAD and visualization systems. The data is translated from STEP Express to HTML using a set of STEP to HTML templates (STML). The ST-Visualizer was used to create VRML files for each of the parts and assemblies in the database. ST-ACIS was used to create ACIS files for AutoCAD for some of the parts. The STEP to CATIA translator in CATIA was used to create CATIA format files for some of the parts. An advanced version of the demo uses OMG CORBA (Orbeline) plus custom code at the VE client site.

Crossing Firewalls. VEs must share information but VE members are separated by corporate firewalls. Eventually OMG ORB/OS Task Force and/or the IETF Authenticated Firewall Traversal Working Group will propose a Secure Peer-to-Peer Internet Messaging standard. In the meantime, Enterprise Integration Technologies (EIT), a NIIIP member, is experimenting with a Post-and-PickUp(PPU) messaging scheme which can be extended to allow data encryption, digital signature, delivery certification, return receipt, message urgency. The PPU scheme relays a message through firewalls via third party called an Exchange Server located in the open outside of any firewall-protected VE client. Client A posts messages to the Exchange Server to the Individual Message Box of client B; Client B independently picks up messages from the Exchange Server. Both the Post and the PickUp protocols initiate from the clientside to the Exchange Server, making it more compatible with commonly accepted access control policies . Different PickUp schemes are being explored: polling, connect-and-hold (involves holding a TCP connection; may not scale) and out-of-band notification (e.g. via email). HTTP and Secure HTTP can readily be adapted to use PPU.