INTERNET MONITORING OF MACHINE TOOLS: THE TIME HAS COME

Nowadays, machine tools can be subjected to a comprehensive data acquisition via the Internet. This no longer concerns just maintenance status. The acquired data can be used for the maintenance, production and management areas. This means accurate statements can be made about the overall costs of a machine over its lifecycle (TCO).

The appropriateness of online services in the machine tool environment has been a topic for several years now and will continue into the future. Whereas several companies already use modern technologies to bring transparency to the associated states of their machines and also to the production processes, other companies are still asking, "For what purpose should we investigate such a protocol of machine status monitoring?"

Does it make sense to spend money for such services? Is it not dangerous for a company to operate machines connected to the Internet? Can the machine status data be used to make decisions for production processes, beyond the obvious maintenance requirements?

All of these questions have been already been addressed by Schwäbische Maschinenwerkzeuge GmbH (SW) (Schramberg-Waldmössingen, Black Forest, Germany), a major German machine tool manufacturer. The company has been providing a comprehensive monitoring of their machine data for many years. ?What is new is that this global data acquisition allows us not only to determine the ideal intervals for use-dependent maintenance, but also to provide customer-specific matched solutions with very useful background information for the production. This gives the management a transparency that it does not have otherwise,? explains Peter Siegel, responsible for the development of online services at SW.

SW was founded in 1994 from the Heckler & Koch (Oberndorf, Germany) machine construction company and since 2004 has been the competence center within the EMAG (Salach, Germany) group for the machining of prismatic workpieces. The company, with its 330 employees, produces approximately 160 machine tools annually that include high-performance 1-spindle to 4-spindle machining centers and special machines.

Approximately 70 to 80 percent of SW customers come from the automotive industry, with other application areas involving medical technology and the hydraulic industry. While SW sells its machine tools worldwide, its main focus is in Europe. A special feature of SW machines is multi-spindle capability coupled with very high precision, in particular the multi-spindle 5-axis machining centers.

End users who want to produce nothing more than "parts, parts, parts" can expect high productivity combined with high accuracy. These machines normally have 12 to 19 NC axes and a working area of approximately 600 mm x 600 mm x 600 mm for a single spindle machine, along with 600 mm x 600 mm x 1200 mm for a multi-spindle model. The company also manufactures jigs because 90 to 95 percent of their end users demand complete solutions, including automation, rather than just standard machines.

Approximately 65 percent of SW machines sold today are connected to the Internet. "However,? notes Siegel, ?by no means do all of our customers fully use the resulting information. Many of them still envision maintenance as only a reaction response to a fault that has already occurred.? However, it is now possible to use this data to perform more activities in advance ? and not only with regards to the operational status of the machines.

Current state-of-the-art technology allows the machine?s operational data to be recorded continuously. Consequently, this permits various conclusions to be drawn and obviously requires that all relevant data be acquired. SW equipped its spindles with sensors several years ago so their status can be checked without requiring them to be removed from the machining head. This enables global data recording to obtain and generate useful conclusions for all of these areas:

? Maintenance

? Production

? Management

?Our services provide the maintenance department with a powerful tool that makes its work simpler and faster,? remarks Siegel. ?The maintenance staff no longer needs to wait for our alerts and updates, because they can also work with the data themselves.?

In production, the same data source can be used to perform other analyses. For example, how often the JOG operation has been selected, how long the setup takes, how long the machine is stopped without any malfunction being present, how long the response time takes for a malfunction, and much more. "All of this data makes it possible to determine the causes of qualitative problems, why processes are instable or why the number of produced parts falls suddenly. Ultimately, a process optimization and/or a productivity increase can be achieved,? states Siegel.

Johannes Zuckschwerdt, a technology development project engineer, uses an example to explain the potential complete data monitoring can achieve: ?During a performance evaluation, one machine had a utilization time of 24 hours, with apparently no optimization potential. The data monitoring, however, showed that the machine was stopped for 100 minutes each day because it was waiting for loading acknowledgements. Assuming a cycle time of 1.2 minutes, 83 more parts could have been processed during this time. For a value of ?8 (~$12) per part, this would mean an added value of ?239,000 (~$358,000) over a year.?

Obviously, this is a purely theoretical value, but even if it is divided by five or ten, a very impressive amount remains per machine! In other words, these monitoring services can pay for themselves very quickly.

Another area benefit from obtaining comprehensive data via ePS is that the operating management can document process reliability in the interest of optimizing production. The is particularly true in the automotive industry, where suppliers require a process validation protocol of some type.

Of particular importance for management is the overall cost of a machine over its lifecycle, the Total Cost of Ownership (TCO). Realistic TCO values require the recording of operational data from actual use. This data can be derived from the previously used condition monitoring records or the acquisition of usage data. Although this allows the lifecycle costs to be calculated over several years, hidden potentials such as process monitoring and optimization remain undiscovered.

Complete data acquisition also discovers things such as creeping process deviations, machine state fluctuations, or resource consumption. This allows these variables to be included in the overall cost consideration while at the very same time it is possible to counter their causes or correct them in a planned manner.

The global data storage on ePS servers also gives machine builders and end users the possibility to prepare comparisons for machines and processes (i.e. location-related issues for end users) and to create reports all the way through to the documentation of process reliability.

SW data gives both the machine operator and its customer security. ?All we need is an Internet access,? says Siegel, ?and our customer receives all of the complete services.? Although this may appear to be simple, in actual practice several hurdles are frequently encountered. Furthermore, there is general mistrust of Internet connections throughout production.

This requires that the IT department is involved in processes of this nature. In the past, IT departments were typically not concerned with NC controllers and other onboard controls. But today, controllers are now part of the global network. It is now necessary to involve the IT department and to open all required communications paths within the company. ?The sooner, the better, as the saying goes,? muses Siegel. Hurdles of this type can be mastered only by communication and the establishing of mutual trust. Existing references will help the builder here.

It is not economical for machine tool manufacturers to provide the data processing platform for all these services,? adds Siegel. ?So, for many years we have been making use of ePS services that support us optimally.? ePS Network Services, a Siemens (Erlangen, Germany) subsidiary, characterizes itself as an Internet-based infrastructure with high-performance servers, storage media and connections to e-mail and SMS text messaging systems, as well as a source for software for the acquisition, preparation and archiving of machine-specific data.

For users, this means "a costing reliability for the construction of Teleservice services, the use of a proven structure and a high data security provided by the ePS Network," explains Jochen Heinz, a consulting team leader for Value Added Services at Siemens. The services are compatible with the current IT security standards. The communication between the machines or service PCs and the ePS servers is limited to the ePS server and uses only certified software components.

Access from external servers is not possible. In such a case, the client server simply does not execute the scripts. The communication is generally only established from the machine or the service PC to the ePS servers. As Siegel emphasizes, ?This, along with an additional encryption, has meant that no data leakage has ever occurred to date.?

What about inter-company aspects for the future? ?When I consider machine components that originate from third parties, such as spindles, then it is now possible to also involve their manufacturers,? responds Siegel. ?We can, for example, provide notification of a soon-pending maintenance or also for a required replacement."

This will certainly have positive effects on spare parts planning. If a spindle manufacturer knows that it will require 20 or 50 spindles for customer "X" in six months, it can schedule such demands into its production forecast. "One could further consider the concept of when a measurement determines 'part worn', an appropriate order action can then be initiated automatically. We want to pursue this direction,? states Siegel.

However, it is important to note, Siegel adds, "We are neither spies nor robber barons, but rather we want to support our customers in the best possible manner, so they can operate their machines without any problems. Our dedicated involvement with our customers in this vital area is proving the value of this ePS service every day.?

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Jochen Heinz is a consulting team leader for Value Added Services for Drive Technologies at the Motion Control Systems unit of Siemens AG, Erlangen, Germany, +49 (7159) 165-411, Fax: +49 (7159) 165-202, www.siemens.com/sinumerik/manufacturing-excellence.

Siemens Energy & Automation, Motion Control Business, 390 Kent Avenue, Elk Grove Village, IL 60007, 847-640-1595, Fax: 847-437-0784, www.SiemensCNC.com .