Intelligent Manufacturing € May € 1996 € Vol. 2 € No. 5

IPC '96: Applying Technology to Processes

By David Blanchard
Editor

One of the most prevalent manufacturing buzz-words in the 1990s is manufacturing execution systems, or MES (see, for instance, virtually any issue of Intelligent Manufacturing for a mention of these systems). This trend toward reducing sophisticated computer-based technologies down to a simple three-letter acronym (CIM, MRP, ERP, PDM, CAM, etc.) threatens at times to send manufacturing managers scurrying for cover. It's a trend R.B. Rowen, systems engineer with IBM's Production Industry Practice (Austin, Tex.) knows all too well.

"Wouldn't it be great if manufacturing really was a black box?" asked Rowen, speaking at the IPC '96 Manufacturing Solutions Show held earlier this month in Detroit, Mich. "An order is placed in one end and the finished, assembled, tested, packaged product came out the other end." While processes haven't quite advanced to that stage yet, the progress achieved in the 1980s and into the '90s -- thanks to robotics, faster computers and programmable logic controllers (PLCs), enlightened human resources, and just plain luck -- has led to the evolution of manufacturing execution systems (MES).

"MES forces you to look at many aspects of the manufacturing environment," Rowen explained, "not only the manufactured product technology, but the support technology and the information content surrounding the manufactured product. The best news is that today's technology and software approaches (e.g., client/server architectures and relational database methods), while not a silver bullet, raise more opportunities than barriers."

According to Rowen, MES applications are filling a gap that he believes will ultimately be filled by a combination of MRP II and SCADA (supervisory control) systems. In the meantime, users of MES systems are typically experiencing a 40% reduction in manufacturing cycle time, for those companies willing to act on the information the system provides.

"An MES project needs to be treated like a new manufacturing line project," he pointed out. "Attention to detail, a phased approach with checkpoints and management reviews are a must. User involvement and feedback must be nurtured and given a greater weight than technical opinion."


Simulating Factory Floor Control
The IPC show is dedicated to various techniques and technologies that affect the manufacturing process, particularly focusing on automation and industrial controls. For instance, Rockwell Software (Milwaukee, Wis.), Allen-Bradley (Milwaukee, Wis.) and Deneb Robotics (Auburn Hills, Mich.) teamed up on the exhibition floor to demonstrate the next generation of virtual factory tools by linking shop floor programmable logic controls (PLCs) to a factory simulation. The integration of control software, PLCs and simulation was made possible due to each company's commitment to open architecture.

The benefits of simulating PLCs and control schemes include the ability to visualize the effect of each input/output signal on factory floor equipment. Simulation will enable programmers to see the operations of a device, or quickly identify fault conditions. The ability to validate control logic will improve the quality of control systems and help reduce the time to launch the manufacturing systems.

In the demonstration, the PLC communicated data to an IGRIP simulation, which served as a visual verification of the sequencing of ladder logic. Any number of devices, sensors, or PLCs can be integrated with the IGRIP simulation.


Videoconferencing Enables Agile Manufacturing
Videoconferencing is a new technology that conjures up images of fanciful science fiction TV shows, such as "Star Trek" or "The Jetsons." However, the technology is already being used in a number of real-world situations, according to John Binder of PictureTel Corp. (Danvers, Mass.), a manufacturer of videoconferencing equipment. "Companies are using video to interact with people at many locations," he reported, for instance: manufacturing, design and assembly rooms; negotiating and managing contracts; and simultaneous engineering. "Many automotive companies and supplier already use videoconferencing linking via microwave, satellite, fiber optics and digital telephone transmissions," Binder added.

Besides its usefulness as a communication medium, Binder sees an even more important role for videoconferencing: as a key enabler of lean and agile manufacturing. "Lean and agile production is the new paradigm that allows all design, engineering, manufacturing and production to be worked on concurrently or simultaneously, with an emphasis on reducing defects and improving overall quality," he explained. The quality of regular communication is vital to resolving issues and solving problems, and that's where videoconferencing can play a big part.

For instance, videoconferencing lets various work groups maintain their physical location while having a "virtual" meeting over video. This would allow the sharing of, say, analysis data or CAD/CAM drawings, which could be altered on a PC application. Videoconferencing also allows a manufacturer to maintain close contact with its OEM suppliers without having to physically travel to the supplier's site, saving both time and travel costs. Ultimately, Binder said, proper use of videoconferencing should result in: better global communications, timely resolution of critical engineering problems, quicker time from concept to production, and the production of better quality products.


Information-Intensive Manufacturing
Referring to a recent report of the National Research Council, J.C. Boudreaux of the National Institute of Standards and Technology (NIST) noted, "U.S. manufacturers are increasingly coming to depend upon information technology -- computers, communications and complex systems that combine the two. Such systems are needed because modern industrial firms, though geographically distributed, still require workers to be linked in complicated patterns of interdependency." A realistic goal, he believes, is to develop an information infrastructure, "whose operational capacity and performance is tuned to discrete-part manufacturing and assembly."

According to Boudreaux, such an infrastructure should be based on distributed systems of "fast, reliable and relatively inexpensive computers linked by high-speed, high-bandwidth networks." An essential element to such an infrastructure would have to include a knowledge base, which would be distributed via knowledge acquisition systems, otherwise known as expert systems. The goal is to collect and then distribute the corporate knowledge of a company's best workers, and to make that expertise widely available through computer-based systems, ideally on a client/server architecture.


Intelligent Manufacturing Systems
Intelligent manufacturing systems, of course, have seen a tremendous rise in interest and applications in recent years, and a number of these systems were profiled at IPC '96. For instance, automobile manufacturer Ford Motor Co. (Dearborn, Mich.) has developed and implemented a real-time plant floor Scheduling Information Support (SIS) system.

This system, based on Gensym's G2 real-time expert system, provides the "on-time delivery of optimally accurate, fully integrated, real-time shop floor status information, all based on asynchronous messages received from a variety of shop floor information systems." The SIS has been implemented in a bumper manufacturing facility, where such operations as molding, bonding, assembly and painting are connected by computer-controlled material handling systems. According to the developers, the SIS has produced significant improvements in scheduling efficiency, and has enabled rapid reaction to production conditions by scheduling personnel.

Ford is also developing applications for intelligent sensor-based manufacturing, which refers to "integration of sensor signals, process models and decision-making techniques to improve the productivity and quality of manufacturing systems." This type of manufacturing includes manufacturing control methods such as adaptive control, intelligent control, neural network/fuzzy logic, and model-based predictive control, as well as sensor-based process monitoring techniques.

According to Ford's researchers, successful laboratory implementations have yet to be duplicated on the shop floor, primarily because of the need for enabling technologies to promote industrial application. One promising sign is that the trend toward utilizing open architecture systems for controllers will help enable implementation of intelligent sensor-based manufacturing.

William VerDuin, general manager of AIWare (Cleveland, Ohio), a developer of intelligent software technologies, reported on recent applications of neural network to process monitoring tasks. Doehler-Jarvis (Stowe, Pa.), a diecaster of aluminum automatic transmission cases, is developing a neural network system to predict important indirect indicators of product quality.

The challenge facing Doehler-Jarvis, according to VerDuin, is "to anticipate and correct problems in a process in which the critical parameters, molten metal flow and temperature distributions are not observable, and the critical portion of the cycle -- the injection -- cannot be modified once it has been initiated." Where neural networks are proving uniquely helpful is in their ability to relate the few process observables to product quality and machine health indicators.

Intelligent capabilities are even being added to such traditional processes as flowcharts. According to Ron Lavallee of NemaSoft (Ann Arbor, Mich.), a provider of industrial automation solutions, "A much-talked-about future trend for industrial automation is the move toward open, modular architecture for control (OMAC)." As a result, flowchart programming for control will be available in Windows NT soon, and in development are such software-based concepts as rule-based "adaptive flowcharts" and 3-D flowcharts that will provide users a better way to visualize complex processes.


IPC Becomes IAM
As a footnote to this show review, it should be mentioned that as of next year, the 25-year-old IPC show (which used to stand for International Programmable Controllers) will change its name to the International Automotive Manufacturing conference and exhibition, or IAM. The show will focus on applied solutions for the transportation industry, and will continue to be held in Detroit.


For more information from IPC '96, click here.