Condition monitoring as an insurance policy

The latest condition monitoring systems and services will reduce the risk and costs associated with unforeseen breakdowns to production plant and machinery, says Kate Hartigan.

When it comes to owning and managing a high cost item such as a car or home, most of us are comfortable with paying insurance premiums, to help safeguard us against unforeseen accidents or breakdowns.

The policy we take out is a type of risk management policy that invariably helps us to sleep better at night.

So, as manufacturing companies, surely we too need to ensure that our high value capital goods, such as production machines and other critical plant equipment, are adequately insured against the cost of unforeseen breakdowns?.

After all, depending on the manufacturing sector you are in, 'lost' production time can equate to anything from tens of thousands of pounds to hundreds of thousands of pounds per day - until the problem is rectified.

Although the cost of a machine component such as a bearing or motor is very small compared with the total cost of the machine, the cost of production downtime and any consequential losses as a result of the bearing failure, are often significant.

For example, take a steel or aluminium manufacturing plant.

The typical cost of production downtime is GBP 100,000 per day.

Similarly, lost production in a paper mill equates to around GBP 15,000 per hour.

Total maintenance costs for a typical food or beverage manufacturer are around 15-20% of total costs.

The pharmaceutical sector also spends similar amounts on maintenance.

Of course, every manufacturing company has a maintenance department to deal with problems like these, but often, because of time and resource constraints, the maintenance team becomes reactive, fire fighting problems around the plant as they occur, with no predictive maintenance systems, little preventive maintenance and often with no maintenance strategy at all.

But there should be no excuses for this today.

There are numerous technology safeguards out there that, when compared with the cost of lost production, are relatively inexpensive.

Using the latest condition monitoring and predictive maintenance systems, including bearing vibration monitoring, acoustic emissions monitoring and thermography to protect plant and machines, is what the more enlightened manufacturers are doing.

But many more firms need to pay heed.

Manufacturing or maintenance managers need to justify any expenditure on condition monitoring systems and services, to their finance director or MD.

We would suggest using a risk management approach for this.

Ask the question of your finance director: "What will it cost the company in lost production if I lose that critical machine for five hours?".

Or "What would you be prepared to pay as an insurance premium, to secure the running of the plant and to protect it against unforeseen breakdowns?".

You may get some very positive responses.

One of the finance director's responsibilities is to ensure that the company's assets are protected.

Risk assessments should be carried out regularly to see what effect breakdowns would have on critical, bottleneck machines and equipment.

The severity and likelihood of breakdowns on particular machines are assessed and given a corresponding risk value.

Those with the highest risk scores are given priority by the maintenance team and should certainly be protected with a condition monitoring device.

Of course, companies can protect their plant without using condition monitoring or predictive maintenance systems, for example, by holding more stock of a particular component such as a gearbox, bearing, coupling or shaft.

This means when a breakdown occurs on a machine, the component that caused the breakdown is available to hand, ready for the maintenance team to fix the problem.

However, as well as the obvious increase in stock holding costs, the company also runs the risk of the stock deteriorating or becoming obsolete over time.

We would recommend that customers reduce the risk of unexpected failures, by implementing suitable condition monitoring systems on rotating plant and machinery.

Don't think of this as capital outlay, but as insurance against the risk of possible lost production.

So what is the true cost of a bearing failure in each of your key production machines?.

By installing a predictive maintenance system, the customer picks up a problem early.

During the next convenient downtime period, the maintenance team can then remove and replace a bearing with minimum disruption costs and also avoid the risk of breakdown damage to the equipment.

Condition monitoring also prevents maintenance teams replacing components unnecessarily and introducing possible new and unrelated problems.

Manufacturing maintenance staff should be using CM systems to predict when failures are likely to occur and plan replacement during production shutdowns.

In too many companies, parts are changed on a time basis rather than on a condition basis because the maintenance team considers this to be the safest option.

However, this introduces a further risk, because whenever there's human intervention, problems can occur.

Most companies work in a breakdown culture which is reactive rather than proactive.

Rather than boasting about how rapidly they can repair or replace components and get a machine back into production, maintenance teams need to be asking themselves "How can we prevent the problems occurring in the first place?".

CM is the most effective solution.

If a manufacturer plans to achieve 100% production schedule adherence, predictive maintenance is critical.

Unforeseen machine breakdowns simply cannot be tolerated.

Similarly, OEE (overall equipment effectiveness), TPM (total productive maintenance) and TOC (theory of constraints) performance will suffer if unforeseen breakdowns occur that disrupt production.

Praxis, a partnership between Schaeffler UK's maintenance and condition monitoring specialist FAG Industrial Services (F'IS) and Corus Northern Engineering Services, gives customers access to the complete range of condition monitoring products and services available on the market today.

This range includes handheld and fixed systems: vibration monitoring systems; acoustic emissions monitoring; endoscopy; thermal imaging equipment; and contract patrol monitoring services.

Training services are also offered, so that the customer can fully understand the equipment, analyse the results and then take the most appropriate corrective action.

The focus here is on customers being trained towards taking complete ownership of the condition monitoring strategy and its implementation.

In the cement industry, F'IS has helped a number of companies eliminate production downtime on tube mills by monitoring the condition of bearings on reduction gearboxes.

The cement manufacturer typically produces at full capacity.

One customer had a three-week shutdown in 2002 due to a damaged gearbox on a tube mill.

The gearbox had to undergo extensive, costly repairs.

To prevent unexpected stoppages in the future, F'IS implemented a condition monitoring system to the plant.

The solution included an eight-channel FAG DTECT X1 system with five sensor measurement points.

The customer's staff were trained to carry out the condition monitoring and received three-months of support in evaluating the data.

The project cost of the CM system including service was Eur 18,000.

Repair cost of severe gearbox damage is Eur 50,000-100,000.

The actual repair cost due to early detection was Eur 5000.

The customer therefore saved at least Eur 27,000 thanks to prevention of consequential damage alone.

What is more, the company avoided lost production amounting to around Eur 6000 per hour.

Extreme operating conditions associated with hot wide strip mills results in a short service life of the work roll bearings.

Unexpected shutdowns and costly resulting damage must be avoided.

Schaeffler's F'IS team therefore installed permanent condition monitoring of the work roll bearings using its FAG DTECT X1 vibration monitoring system.

This included integration into the customer's own software, remote monitoring, evaluation of the data by F'IS experts; training of the customer's staff; and the reliable identification of all bearing defects.

As a result, the customer prevented unforeseen breakdowns and the cost of any consequential damage.

After less than a year from installing the new systems, the customer projected the following results.

The annual costs before introducing condition monitoring were: five chock/roll neck repairs, each costing Eur 21000 = Eur 105,000; and five unscheduled roll changes, each taking 7 minutes = Eur 35,000.

The total was Eur 140,000; whereas the total CM project costs by comparison was Eur 100,000, producing total savings from condition monitoring system of around Eur 40,000.

In the paper industry, F'IS worked with a customer who demanded a very high level of plant availability, around 97%.

Goods are shipped immediately, therefore any unexpected stoppages to production cause significant losses.

Depending on the product quality, the loss of production equates to between Eur 10,000 and 30,000 per hour.

In 2004, to safeguard the availability of the machine, F'IS installed its online condition monitoring system, FAG VibroCheck.

The customer's engineers were trained by F'IS and are now operating the system without external help.

The customer is supported by F'IS with online remote monitoring.

The online CM system FAG VibroCheck monitors 128 sensors positioned on rolls in the wet section and in the dryer section.

The required additional signals (such as speed) are provided via an OPC server and used by FAG VibroCheck to monitor the machine.

Alarms are sent to maintenance via an alarm log.

When new alarms are triggered, reports are sent to the central control station via a second data acquisition card; these reports are also displayed to the paper makers.

After installing the new CM system, the customer detected damage to one of the MG cylinders.

The sensor at one of the bearings that supports the MG cylinder (diameter 6.1m) automatically triggered an alarm.

Confirmation by F'IS remote diagnosis experts was that there was outer ring damage detected at an early stage.

The necessary repair work was carried out one week later during a scheduled shutdown.

Two F'IS fitters, supported by the customer's own staff, replaced the bearing, a task which took 30 hours to complete.

Due to early replacement, no consequential damage was caused to the roll neck (cost around Eur 50,000, several days delivery period).

If consequential damage had developed, the repair would have taken more time - at least 18 hours longer - and that is assuming a spare roll neck would have been available.

Customer savings amounted to at least Eur 230,000 (18 hours x Eur 10,000 per hour = Eur 180,000 production loss + Eur 50,000 roll neck damage).

How much is it worth to keep your factory running?.

Kate Hartigan is Managing Director of Schaeffler (UK).

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