Condition Monitoring: Some Economic Issues

01 September 2007

New ways to gather information, such as wireless networking, plus information integration are helping users avoid costly downtime on their equipment.

Wireless sensor networks, once objects of curiosity, are increasingly moving into the mainstream as ways to gather information on equipment. Self-organising meshes of inexpensive wireless vibration sensors, for example, can watch for trouble and allow maintenance personnel to intervene before equipment malfunctions.

Wireless systems are especially suitable for plant renovations, says Neil Cooper, of Invensys Process Management, where people are just trying to figure out how they can get value out of what they already have in place. And in a plant without an existing digital communications system, he continues, ‘the wireless infrastructure is now robust enough and low cost enough that people can consider networking areas of the plant that they wouldn’t have gone after traditionally.’

Stuart Harris, of Emerson Process Management’s Asset Optimisation division, points out that it’s only recently that wireless networks have begun to be integrated into larger systems. As standardisation moves ahead, major automation suppliers are climbing aboard, offering wireless sensing equipment as part of their larger offerings.

Levels of integration
Manufacturers are increasingly recognising the need to integrate condition monitoring coupled with asset
management into the larger corporate structure. This integration, says Mr. Harris, has three levels.

First, he says, is a drive for integration of predictive diagnostics into a suite of applications. Many vendors have provided solutions for small subsets of the installed assets, leading to one application for vibration analysis, a different tool for control valve diagnostics, and yet another for an ultrasonic program. Today’s trend is the integrated suite, where the diagnostics from across that whole breadth of plant assets comes together. Bringing that information together ‘will provide more information for things like management
dashboards and key performance indicators.’

The second level is the integration of asset management and process control. This allows operators to see what’s going on with the health of assets and respond accordingly. An operator can, for example, spot the beginning of cavitation and alter process conditions to prevent equipment damage.

The third level is integration to the enterprise level with a completely integrated asset management, control
system, and safety system. It’s probably a few years away.

Business issues
One thing that has slowed the adoption of modern condition monitoring and asset management practices has been that the people making the investment are not necessarily the people reaping the rewards.

‘Historically, there has been a little bit of a disconnect between the measures for condition monitoring and reliability and the plant economics or the payback,’ says Mr. Harris.

And there are some who question whether asset management by itself is the golden route to plant optimisation. They ask this question: If a plant’s maintenance department could do a 100% perfect job, and keep the plant in top repair, so that there was no machine downtime, would that lead the way to maximum profitability?

Dr. Peter Martin, of Invensys, offers what seems to be a counter-intuitive answer. He says that maximising a plant’s economic value does not result from pushing maintenance to achieve optimum availability and at the same time stretching the operations department to achieve maximum utilisation (diagram). It comes from a recognition of the limitations of the two departments and striving to achieve a balance between the two. Dr. Martin and his group say they have figured out how to quantitatively measure availability and utilisation and analytically determine the optimum balance. This is the core of Invensys’ InFusion product, released last year.

Dr. Martin offers a simple example: A certain gas processing plant running 48 compressors achieved 85% utilisation by running them at full speed. ‘Not bad,’ some would say. But, on the average, three compressors would break down a month and require repair. This is why the utilisation was 85% and not 100%.

By installing variable speed drives and doing some experimentation, the company found that running the
compressors at 98% of full speed would only cause one of them to break down every six months. The utilisation increased to 92%. ‘This may be counter-intuitive,’ says Dr. Martin, ‘decreasing the instant
utilisation in order to increase the overall utilisation.’ But that’s exactly what the evidence suggests.

Outsourcing
Competitive pressures and the loss of key personnel through retirement and costreducing operations are causing many companies to look closely at subcontracting their condition monitoring and asset management functions, says Scott Teerlinck, of Rockwell’s Plant Services business. They do this so they can focus on their own core competencies.

This trend has caused condition monitoring and asset management to grow into a multi-billion dollar business. In 2005 the ARC Advisory Group predicted the worldwide market for Plant Asset Management (PAM) systems would grow nearly 10% per annum, from $1.1 billion to more than $1.8 billion by 2009.

Some of the largest control and process management vendors are adding these services to their portfolios. Invensys Process Systems’ Avantis unit offers Avantis.Pro enterprise asset management (EAM) software solution and the InFusion Condition Manager; Rockwell Automation offers RAAMP, which includes MRO process management as well as spare parts management services. Emerson Process Management’s
PlantWeb digital plant architecture is built around the concept of detecting process and equipment problems before they occur, so that users can move from reactive to proactive management. Flowserve has a suite of asset management tools for valves, actuators and positioners.

While some companies are outsourcing much or all of their condition monitoring and asset management functions, says Mr. Cooper, others decide to keep the monitoring of their critical, large-scale heavy impact equipment in house, but hire a managed service to look at the balance of the plant. ‘In a power plant, for example, the owners might choose to monitor the boilers and turbine, but will contract out the monitoring of the coolers, preheaters, cooling tower fans and cooling tower pumps.’

Loss of knowledge
Some people worry that outsourcing condition monitoring and asset management may accelerate the decline of in-house skill levels. What about the crucial knowledge and expertise that exist only in people’s heads and are critical to keeping the plant running? ‘They’re losing it, anyway,’ says Mr. Cooper. ‘All the engineers that built the plants are the same age as the plants, and they’re all retiring.’

Another factor in the loss of in-house expertise is that engineers are not receiving sufficient training in the field. The reasons, says Mr. Teerlinck, are economic, financial, globalisation and demographic—‘every ten retiring workers [are] being replaced by three to seven.’

Training is a big part of the services that have to be provided by an asset management supplier and it’s important to set up programs to make sure that people are aware of the technology and make proper use of it.

Yet just getting the software is insufficient; you have to follow through. ‘We’ve got instances where asset
monitoring systems have been put in and created alerts that were not paid attention to,’ says David Ochoa, of Emerson Process Management. ‘The process wasn’t really there to communicate effectively within the plant and react appropriately to the diagnostic,’ he adds.

Asset management outsourcers can counter that problem, says Mr. Teerlinck, by bringing in subject matter experts, and bringing in resources to work along side the existing team members ‘to make sure that what we’re doing is aligned with the strategy of that manufacturer.’ They may also hire some of the manufacturer’s own people.

Condition monitoring and integrated asset management are no longer optional for most companies; they are essential. Fortunately the means to achieve them are more available then ever before — if you’re willing to take the effort to really learn what’s going on in your plant and then make wise choices in addressing the issue.

—article based in part on material from Peter Cleaveland, Control Engineering


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