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PDM and the Internet PUBLIC ACCESS

Browsers Can Expand Product Data Management to Thousands of People in Manufacturing Who Have a Need to Know.

[+] Author Notes

Alan Mendel is director of North American consulting operations at CIMdata Inc., Ann Arbor, Mich.

Mechanical Engineering 121(09), 60-63 (Sep 01, 1999) (4 pages) doi:10.1115/1.1999-SEP-3

Internet technology is reshaping the product data management (PDM) software business. Product data management on the Internet is a natural extension of this distributed arrangement. The Web browser essentially becomes a new kind of client, one that's uniform across all applications. Currently, most PDM servers are simply not configured to handle so many concurrent users, and the processing burden assumed by the client in the client/ server system shifts to the server in a browser-based system. One of the main reasons for the increase in Internet activity for PDM is the success of the World Wide Web throughout society and business. The primary security mechanism currently used on PDM systems is the use of passwords that identify users, telling the system what each person can see or change. While client/ server systems maintain state, Internet communication between a browser and a host typically is stateless; that is, once the server satisfies the request for data from the browser, it completely forgets about the existence of the browsers and maintains no pointers linking the user to the on-line database.

Internet technology is reshaping the product data management software business. Just two years ago, . Internet capabilities had barely made a dent in the way engineering companies managed information. It was only in June 1998 that Parametric Technology Corp. of Waltham, Mass., released the first PDM system architecture based on Internet technologies. Today, html/Java-based Web user interfaces and Web-based server access have become basics in PDM systems.

The impact of the Internet on PDM follows big changes in the industry as a result of the workstation client/server movement in the late 1980s that led companies away from mainframe-based systems.

The distinct advantage of the client/server model is that it puts application power on the desktop, where it runs at the convenience of the user rather than of the mainframe scheduler.

Instead of having all software running on the central mainframe, systems for this distributed arrangement have core PDM software residing on a server connected over an internal network to several workstations. Each workstation, or client, runs software to perform actions such as displaying contents of the product structure, searching for information, or executing a workflow task.

Product data management on the Internet is a natural extension of this distributed arrangement. The Web browser essentially becomes a new kind of client, one that's uniform across all applications.

Users who have accessed the Internet for other purposes in their work and personal life want to interact with PDM in a similar manner. They question why they can't use a simple browser on their desktops as a convenient point of access to the PDM system.

Such user-driven movement has sent vendors scrambling for ways to accomplish this, and this year almost all PDM products available offer standard Internet browsers. The market has responded well to this type of feature, and users are demanding more capabilities from all systems.

Diagram illustrates the Internet-based architecture and standard development tools approach used by Parametric Technology in its Windchill software.

Grahic Jump LocationDiagram illustrates the Internet-based architecture and standard development tools approach used by Parametric Technology in its Windchill software.

A screen using Unigraphics Solutions' Web-based data management interface, iMan. Such systems use browsers as convenient ways to consolidate information.

Grahic Jump LocationA screen using Unigraphics Solutions' Web-based data management interface, iMan. Such systems use browsers as convenient ways to consolidate information.

There are trade-offs in performance in using the Internet for PDM systems. Currently, most PDM servers are simply not configured to handle so many concurrent users, and the processing burden assumed by the client in the client/server system shifts to the server in a browser-based system. Moreover, Internet bandwidth is much narrower than the bandwidth in most client/server systems so that data cannot pass as quickly.

One solution to the performance problem is to reserve Web-based interfaces for more casual users who want access to product data but do not need to manipulate it. On the other hand, power users, who create and modify data, need access to the most robust functionality that a PDM system can offer.

The Internet has influenced the pricing, as well as the features, of PDM systems. For a client/server arrangement, prices essentially were charged per client or according to some other licensing arrangement.

This software-licensing model was broken by the use of browsers, which allowed many concurrent users on intranets within companies. As far as the PDM system was concerned, companies had only one client.

Pricing models changed to account for registered numbers of users as well as the numbers of concurrent users. Transaction-based pricing models, in which customers are charged for time on the system and types of operations performed, will most probably develop over time.

One of the main reasons for the increase in Internet activity for PDM is the success of the World Wide Web throughout society and business. The Internet started out as an information service with a variety of tools and ways of accessing databases. These all had different protocols and were generally not easy to use.

The World Wide Web changed all that with the hypertext transfer protocol and the hypertext markup language (almost universally recognized as the abbreviations "http" and "html"). Together, these technologies allow the creation of formatted pages, which can be "hot-linked" to other pages. This provides users not only content that looks good but an easy way of navigating to related information.

The two key software components of the Web are the browser and the http server. A browser, such as Netscape Navigator or Microsoft Internet Explorer, communicates with the http server, a program that listens for and accepts requests for information from the browser, then looks for a predefined page with appropriate information or causes a program to be run. These programs, called scripts, can issue a query to an external database or communicate with a PDM server. The program is run through something called the common gateway interface. Users enter a uniform resource locator address for the Web page into the browser, and off it goes.

One of the big attractions of the Web is the simple interface through standard browsers, which are inexpensive, simple to understand, and capable of supporting almost all users. The programs run on all types of computers, Unix workstations, PCs, and Macintoshes, providing the same look and feel across all platforms and for all applications.

Browsers are seen as a way of expanding PDM to thousands of people in the manufacturing enterprise who otherwise might not have convenient on-line access to this broad base of information.

A script can be written to retrieve information from multiple sources and present it in a single view to the user. This includes not only data from the PDM system, but also information from the shop floor, parts management systems, purchasing, finance, shipping, and legacy systems. Data displayed on the PDM browsers is not truly integrated and, in most cases, databases remain separate. The browser provides a convenient way of consolidating information in a single place.

Inside view of a work in progress: A Netscape browser is the medium allowing the inspection of the suspension .. .

Grahic Jump LocationInside view of a work in progress: A Netscape browser is the medium allowing the inspection of the suspension .. .

Security is always a valid concern in handling proprietary information, so companies must put ample measures in place to control access to information. The entire system is no better than its basic security features.

The primary security mechanism currently used on PDM systems is the use of passwords that identify users, telling the system what each person can see or change. Three weaknesses of passwords are the same for any network. That is, a user may somehow divulge a password to others, or may choose a password (say, a first name) so obvious that it can be easily guessed by intruders, or someone may leave a terminal unattended after logging on.

The added danger with the Internet is that information access is provided across a wide area, unprotected by the security firewalls most companies have in place to isolate their systems from the outside world. On the Internet, it's often difficult to identify and trace who is accessing your system and what they are doing.

Information is transmitted across the Internet in broadcast fashion, with packets of data streaming around any l1Lunber of routes before being received by a system with the appropriate address. The Internet originally was set up this way for universities and defense agencies to transmit information during a time of national emergency, when some nodes of the communication network might be destroyed. Unencrypted data broadcast on the Internet becomes visible and vulnerable to those who know how to retrieve it, just as radio conversations can be heard by any one who has the right equipment.

Unscrupulous people who want to access information intended for others can connect a computer programmed to accept all packets it finds on the Internet. Then with. the aid of off- the-shelf search engines, they filter through the messages until they find transmissions of interest to them. Simple e aves dropping is often the motive of such Internet hackers. But some may want to sabotage companies and individuals by modifying, blocking, or otherwise interfering with these transmissions. To make matters worse, it's often difficult to tell when this has happened.

A variety of network security services are available that encrypt servers so that programs and data are intelligible only to users with proper decryption software. Incorporating such security services is certainly an opportunity for the PDM community to add value to the products it offers. Some PDM software vendors offer turnkey packages that include the Web security on top of the ordinary security of the PDM system.

... Or of the interior of an automobile in development. The software used is Division Group's ProductView.

Grahic Jump Location... Or of the interior of an automobile in development. The software used is Division Group's ProductView.

Most PDM systems today offer some type of Internet capability. Generally, they have at least a report writer that generates htm1 Web pages so information can be viewed on the client's browser. Some systems let users access information made available on the Internet by third-party vendors, mostly component parts data and bills of material information.

Perhaps the least demanding users of PDM systems on the Internet are information consumers. They receive downloaded data that they request by typing in queries.

Two-way graphical browsers created by applying technology such as Java now allow users to enter and modify data as well as to access it.

A step ahead of information consumers, who usually look at static text and tables, the information reviewer is able to access data more dynamically and manipulate it slightly on-line with operations such as document and drawing markups, for example. Delivering such capabilities requires small programs called helper applications downloaded along with the data if they do not already exist in the user's computer. Written with languages such as Java, these "applets" give the user's machine power to return on-line comments back to the PDM system, for example, and to view different file types not native to the browser, such as DXF or IGES.

Moving to satisfy requirements for an even more advanced class of users, the information creators, PDM systems are now launched with even stronger two-way protocols. These allow users, for example, to upload files for check-in and check-out and to interact with these files on-line in adding and modifying information, just as with today's client/server PDM systems. The difference is that these new Web-based systems give users access to a much broader base of data and al-low a single user to influence a much wider range of applications throughout the system than was previously possible.

One of the major hurdles to overcome in performing such context-oriented functions is that they require the system to maintain state; that is, to maintain knowledge of where the users are as they navigate from point to point in the database. This capability is necessary for strong two-way communications, so that users' actions (such as adding or modifying a component in a database) have a context that ties the users to the database until operations are completed and the users sign off.

While client/server systems maintain state, Internet conu11unication between a browser and a host" typically is stateless; that is, once the server satisfies the request for data from the browser, it completely forgets about the existence of the browsers and maintains no pointers linking the user to the on-line database.

Providing such context-oriented functions, given the current protocol of the Internet, is a major challenge to overcome before strong two-way PDM communication becomes available on the Web. This work is proceeding in the WWW consortium, the standards body that oversees the World Wide Web, and eventually will be embodied in standard protocols.

Copyright © 1999 by ASME
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