Software tools boost OEE

Overall equipment efficiency (OEE) is a key statistic in any manufacturing facility, so it can be particularly problematic when one of your most common machines is only running at 60% to 70% of its potential. Such was the case when Moen, a Fortune 500 manufacturer of kitchen and bathroom faucets, approached Rockwell Automation to help improve equipment efficiency, increase throughput, and reduc...

By Matt Bauer, Rockwell Automation July 1, 2008

Overall equipment efficiency (OEE) is a key statistic in any manufacturing facility, so it can be particularly problematic when one of your most common machines is only running at 60% to 70% of its potential. Such was the case when Moen, a Fortune 500 manufacturer of kitchen and bathroom faucets, approached Rockwell Automation to help improve equipment efficiency, increase throughput, and reduce downtime.

Screw machines—which are essentially a form of highly automated lathe—are essential in faucet manufacturing. In a screw machine, a set of mechanical feed fingers pulls a long rod of copper, brass or other raw material into the machine, which automatically forms the metal into the appropriate shape for the faucet piece and advances the rod to make the next part. A bar loader moves from machine to machine to provide each station with plenty of raw stock. Many modern screw machines track the number of faucet pieces produced from each rod, allowing manufacturers to accurately predict supply needs and help prevent work stoppages.

In general, older screw machines do not have the ability to accurately count the number of parts produced. Rather than count individual parts, they weigh large quantities on bulk scales and then estimate based on the piece weight. These estimates provide some guidance on raw material use, but if a bar loader is unable to manually detect a rod shortage, the machine can shut down entirely, sacrificing productivity. Rod shortages and feeding errors in screw machines can also lead to increased product flaws, forcing many manufacturers to submit to labor-intensive quality checks—which are particularly problematic when more than 100 products are in production at any given time.

“The main reason we automated our production with Rockwell Automation was to provide a better handle on our productivity,” said Steve Zurcher, lead production coach, Moen. “What we didn’t expect was a tamper-proof way to count parts and monitor machine operations, with the ability to compare cycle time to rate.”

Accurate count needed

Moen sought a solution that would provide an accurate count of the number of parts each screw machine operator produced in a given day, which would allow the company to identify potential problems before they occurred, and improve overall efficiency. In addition, the faucet manufacturer needed to confirm that each machine was running at maximum availability.

“With increased competitive pressures, the ability to keep close tabs on our productivity and keep it as high as possible was becoming increasingly critical,” said Zurcher. “This requires reliable access to operation data, including rate versus cycle time, part counts, and overall operating parameters of our machines.”

Moen set its sights on managing its facility with a comprehensive plant-wide reporting solution available through the Rockwell Automation FactoryTalk integrated production and performance software suite. By bringing a simple view into plant operations, without adding additional personnel, the service-oriented architecture within FactoryTalk could provide Moen with a tailored mix of software integration tools and manufacturing software applications for improved access to plant-floor information.

Data from many different operations across the plant floor is now fed into one software application, FactoryTalk Metrics. Engineers can use the data to help improve processes and generate reports on production development. This allows them to more easily adjust their manufacturing operations to meet ongoing product demands. Whereas operators previously logged delays manually—and sometimes inaccurately—the FactoryTalk Metrics component of the manufacturing execution system (MES) now automatically logs delays in a fraction of a second. The software also serves as a basis for understanding the real causes of inefficiency, waste, lost capacity, and equipment status.

Moen also uses FactoryTalk Transaction Manager software to more effectively integrate the critical data in its shop-floor control systems with enterprise IT and other manufacturing applications. With this application, Moen is able to establish a two-way exchange of data between applications, a database, and the existing control system to download recipes or production schedules.

Moen is also able to take advantage of Rockwell Software’s RSLinx communications interface software, which enables the control platform to provide data simultaneously to multiple applications, including FactoryTalk Metrics and FactoryTalk Transaction Manager.

Moen extends its data collection capabilities to the device level with a DeviceNet communications network. Moen can collect operating parameters, such as power, current amperage, line output, fault codes and bus voltage, or pull up a trend analysis for a specific component to see how well it is doing. Engineers use an RSNetWorx software interface to define and configure device management services for DeviceNet.

The Rockwell Automation solution helped Moen boost productivity by 10% in less than one year. Moen increased OEE on most machines by nearly 30% as a result of its ability to accurately determine the number of pieces each machine produced. The machine part count data also allows management to schedule preventative maintenance and minimize downtime. The faucet manufacturer is now able to tell how long its equipment is running and how many parts each line is producing, as well as verify overall cycle time versus rate without resorting to weight-based estimates. In addition, Zurcher and his team can also tell when a machine breakdown is coming, due to voltage and cycle time increases, he said.

Author Information

Matt Bauer is director of Rockwell Software commercial marketing, Rockwell Automation. For more information, visit