Wireless as a means to overall equipment efficiency

Accurate machine run-time data helps determine why production goals aren’t met.

09/07/2017


With a wireless system, using a tower light with a wireless radio base offers more than just local indication of machine status. Courtesy: Banner EngineeringField devices make operations visible and support data-driven decision making. Using technologies associated with the industrial internet of things (IIoT), device-level data is accessible to operators and plant managers, offering insight into machine performance and process inefficiencies.

Real-time remote monitoring of machine status allows addressing issues as they arise, regardless of whether an operator is present. Personnel monitor multiple machines on a factory floor from a convenient location. Operators resolve small issues before they become big problems.

Let's look at how wireless technology provides users with remote-monitoring capabilities on the field-device level and how this data can be used to help improve overall equipment effectiveness (OEE).

In the past, wireless systems were difficult to install and complicated to maintain. Wireless technology has advanced significantly over the years. Today many remote monitoring solutions offer reliable wireless communication integrated into a single, inexpensive unit. These wireless I/O devices are easy to install, and then uninstall and move to a new location as monitoring requirements change.

A single wireless I/O device can collect both digital and analog sensor readings and forward this data to a central collection point for analysis.

Furthermore, several sensors can connect to a single node, and 47 nodes can exist within a single radio network. This means multiple sensor readings aggregate into a single gateway device before being forwarded to a host-controlled system for analysis.

Serial-data radios further extend this wireless I/O network. Serial-data radios are back-haul devices that receive serial data from another serial-data radio, or a serial connection to a gateway, and forward the data to another remote serial device. Chaining data radios expands the network to meet the remote-monitoring needs of many applications. 

An efficiency calculation

Overall equipment effectiveness (OEE) is a calculation of manufacturing process efficiency involving three primary factors: availability, performance, and quality. The availability factor considers events that decrease total runtime, including planned stops (such as for product changeover) and unplanned stops. The performance factor considers anything that decreases the speed of the manufacturing process while it is running. The quality factor accounts for parts or products that do not meet quality standards (parts that must be scrapped or reworked, resulting in wasted time).

An OEE calculation taking these factors into account expresses its result as a percentage value, with 100% meaning only good parts are made (quality), as quickly as possible (performance), and without any stops (availability). Calculation results provide actionable insights into the critical sources of waste in a manufacturing operation.

The OEE Foundation also identifies 6 "Big Losses" to manufacturing productivity: 

  • Unplanned stops for equipment failure
  • Stops for setup, adjustments, or changeover
  • Idling or minor stops (for issues such as a material jam or a blocked sensor)
  • Reduced equipment speed
  • Scrapped work
  • Rework.

To reduce these losses and minimize their impact, visibility into where and when inefficiencies occur is essential. This is where access to data from sensors and indicator lights become very important. Logged data from sensors and indicator lights installed on machines can help calculate OEE and identify steps to improve efficiency of your machines, processes, and people. 

Machine runtime trends

Tracking machine and process data trends helps identify when and where losses are occurring. However, manually monitoring production machine status is time-consuming. Depending on facility size, manually monitoring machine status slows down production and requires additional man-hours more effectively used elsewhere.

With a wireless system, on the other hand, using a tower light with a wireless radio base offers not only local indication of machine status but also remote status of each light module. By logging results from machine-status indicators like tower lights, users can track trends in individual machine up-time and cycle counts for timely updates.

Data can be used to identify whether a bottleneck is caused by a machine or personnel issue. Capturing machine status helps users identify causes of production loss. This information, necessary to identify and drive efficiency improvements, was most likely previously unavailable.

This was the case recently when for one manufacturer accurate machine runtime data helped determine why production goals were not being met. Operators blamed machine downtime for the failure and maintenance personnel blamed the operators. Based on the data, facility managers identified what exactly was transpiring. 

A machine's health

In addition to monitoring machine performance metrics, wireless sensor networks also check up on machine health. Machine predictive maintenance is challenging because minor performance changes can be hard to detect without the proper tools. Remote condition monitoring using a wireless system plays a key role in predictive maintenance and helps prevent costly downtime.

To take just one brief example, vibration is a key machine parameter. Machine vibration is often caused by imbalanced, misaligned, loose, or worn parts. As vibration increases, so can damage to the machine.

By remotely monitoring of motors, pumps, compressors, fans, blowers, and gearboxes for increases in vibration, problems are detected before they become severe. A wireless vibration and temperature sensor serves as a "check engine light" for machines by measuring RMS velocity, which provides the most uniform measurement of vibration over a wide range of machine frequencies.

After mounting the vibration sensor, a user must collect enough vibration data to establish a baseline for the machine. Initially set the threshold at 1.5 or 2 times the baseline. When the threshold has been exceeded, the wireless vibration and temperature sensor can provide local indication of the problem, the signal can be sent to a wireless tower light on a central location, or an email or text alert can be sent. The vibration and temperature data can also be sent to a wireless logic controller or programmable controller for collection and analysis. 

Final words

Remote monitoring capabilities are making it easier for manufacturers to identify and remedy causes of waste within their facilities. By utilizing wireless technologies, manufacturers can quickly and easily gather data needed for OEE calculations, as well as gain valuable metrics for predictive maintenance to maximize their machines' performance.

Fritz Cleveland is product manager, wireless products, at Banner Engineering.

This article appears in the IIoT for Engineers supplement for Control Engineering and Plant Engineering.

- See other articles from the supplement below.



The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
A new approach to the Skills Gap; Community colleges may hold the key for manufacturing; 2017 Engineering Leaders Under 40
Doubling down on digital manufacturing; Data driving predictive maintenance; Electric motors and generators; Rewarding operational improvement
2017 Lubrication Guide; Software tools; Microgrids and energy strategies; Use robots effectively
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Mobility as the means to offshore innovation; Preventing another Deepwater Horizon; ROVs as subsea robots; SCADA and the radio spectrum
Power system design for high-performance buildings; mitigating arc flash hazards
Research team developing Tesla coil designs; Implementing wireless process sensing
Commissioning electrical systems; Designing emergency and standby generator systems; Paralleling switchgear generator systems

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
Featured articles highlight technologies that enable the Industrial Internet of Things, IIoT-related products and strategies to get data more easily to the user.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me