Optimal production planning requires high-quality tool and technology data, and the Siemens Energy Inc. plant in Charlotte, N.C., takes a comprehensive approach to that task: 'network manufacturing'. Those two words describe a continuous exchange of experiences between the production processes and the planning functions, supported by a tool data management (TDM) system. The operators store “knowledge” about tools and their use as “work instructions” in TDM, which directly benefits planners and NC programmers. This establishes the parameters for a consistently high-quality production process: errors in planning and production are avoided, machine downtimes reduced, and productivity rises.

Siemens’ power generation business develops systems and technologies for low-CO2 electricity generation, products that emphasize a high level of efficiency in order to reduce fuel consumption. Currently, it is building a combined-cycle power plant that will have an efficiency rating in excess of 60 percent. State-of-the-art technology is contributing to the efficiency of fossil fuel-fired power stations, to achieve some significant reductions in CO2 emissions.

At the plant in Charlotte, about 1,000 employees are producing components for generators, for gas and steam turbines. CNC machines are used to mill, turn, and drill workpieces, and to hob and turn turbine blades, rotor blades, and housings.

“We have mastery of the entire range of machining processes,” according to Klemens Huch, generator operations manager at Siemens Energy Inc.

“On our numerous machines, complete items are produced with very high precision in just a few clamping operations,” he continued, summarizing a complex production process that involves more than 100 CNC machines. The vertical integration of the plant, and the high volume of parts to be produced for a wide range of turbines and generators, entails a correspondingly large number of tools. More than 10,000 tools are in use by the machines, and together these comprise more than 30,000 component parts.

Tools, adapters, and fixtures, etc., including their technology data, all require clearly structured management in order to avoid duplicate orders and redundancies, and thereby to save costs. Moreover, all of that data is needed for programming the plant’s operations.

Until a few years ago the Charlotte plant used a materials management system it had developed internally. It had reached its limit for expansion, and functionality.

“On the one hand, our old system was incapable of mapping and storing tool graphics. On the other, data maintenance was elaborate and complex,” Huch recalled. “The tool data was incomplete, which rendered them useless for many further processes.”

As a consequence, the production cells could not always rely on the tool selection in the generated NC programs. Particularly when it came to the processing of new workpieces on the CNC machines, the machine operators had to proceed very carefully in order to avoid any risk of collision. “Sure, even then we’d try to simulate the production process,” recalled Siemens Energy manufacturing engineer Eric Graber, “but the lack of adequate data maintenance for our production equipment management rendered this impossible under real-life conditions, and t represented an additional process risk.”

Often, this situation resulted in discrepancies between the NC programming and production staffs, and mutual acceptance was low. “We could never rely one-hundred-percent on the programs,” Graber explained. “If we wanted to work with any degree of process stability, we had to run in new processes very slowly, to avoid collisions, … which was very time-consuming.”