Using a smart condition monitoring (SCM) system, operators can now gain access to a ‘crystal ball’ regarding the status of rotating equipment. The system can raise the alarm, predict failures in advance and provide information on recommended actions to take, all allowing for more cost-effective asset management, which, in turn, helps to continually avoid unplanned production downtime events and the associated excess maintenance costs.
For example, if a mixer or a refrigeration unit fails in a food or beverage processing plant, the drop in productivity alone can cost thousands of pounds per hour, which is often compounded by the further cost of wastage and unplanned maintenance. Such units should be considered ‘primary assets’ – assets which, if unavailable, can bring whole sections of a plant to a total standstill. Preserving the efficiency of these primary assets is therefore paramount to meeting KPIs and ultimately achieving profitability. “With recent developments in modern sensor technology, businesses can now engage in ongoing monitoring activity in a reliable and cost-effective manner,” says Chris Evans, marketing and operations group manager at Mitsubishi Electric. “As a result, it has never been easier to avoid the catastrophe of unplanned downtime - the nightmare of production and maintenance teams across the food and beverage industry. Smart Condition Monitoring relies primarily on developments in sensor functionality, networking and the use of smart controllers to provide continuous monitoring.”
Driven by technology
With advances in technology, a wide range of factors can be automatically monitored and cross-referenced by an SCM, including vibration characteristics, operating temperatures, drawn current and shifts in operating parameters. The system utilises multiple smart sensors, physically attached to the asset (using glued, screwed or magnetic fixings), which feed back information via Ethernet to an advanced sensor controller.
“The solution can be used as a self-contained, stand-alone device (ideal for feasibility studies or trials) or as a fully integrated system, allowing information to be transmitted across the factory for easy access via HMIs on the shop floor, to PCs connected to higher level data systems, or to mobile devices over local Wi-Fi, the internet or mobile networks,” Evans explains. “The crucial data analysis is performed on board the PLC, so the system can be relied upon to transmit simple, but accurate, overviews or warnings to operators in real-time prior to any significant asset failure.
“An intuitive graphical interface, as with many of the latest automation technologies, is vital for operators to diagnose potential issues without expert knowledge. Utilising the installation of HMIs configured to display basic parameters, the system can automatically create conditions and alarms with an associated text description. Diagnostics can be configured to display all data regarding an asset or a general overview that can be simplified into a traffic light alert system, displaying overall condition for ease of assessment. Thanks to an associated app, operators can also use a mobile device to monitor the status of equipment while on the go.”
Once in operation, a SCM system can detect a wide range of potential issues. These include bearing defects from races or balls and rollers, motor imbalance, misalignment, instability, resonant frequencies, breakages, blockages and low levels of lubricant, temperature fluctuations and phase failure in power components. From these faults, the system can then offer suggestions for future operation, more precise error identification and trend analysis.
The power of sensors
By spreading sensors around the plant and including information from other automation systems, the reach of SCM goes far beyond the more traditional methods that would typically concentrate on a specific power transmission component. This means that many smaller ancillary systems can also be connected economically, reaching out from primary assets to consider a more holistic, and therefore far more effective, encompassing view of the production facility itself.
“The importance of such systems has increased, as production managers are now required to attain a reliable ‘future’ plant, with new approaches needed to allow for increased digitisation and ensuring the adaptability of processes for future technological development,” Evans explains. “These trends have seen the demand for condition monitoring systems increase over the last few years, which is not likely to slow down - given a number of market sources are predicting the industry will undergo compound annual growth (CAG) of up to seven per cent for the period to 2020.”
The cost to the industry of not adopting an SCM approach is equally as daunting: a report from international business analysts Dunn & Bradstreet indicates that 49 per cent of Fortune 500 companies experience at least 1.6 hours of downtime per week, which is the equivalent of two working weeks a year. Downtime cost estimates for food producers vary wildly from hundreds of pounds per hour to tens of thousands, depending on the size and nature of the process, so, cumulatively it’s clear the cost to the industry is huge. As global competitiveness increases, those with an advantage are likely to take the spoils.
By utilising a smart approach with regards to condition monitoring, proactive maintenance can become part of the plant system architecture, providing continuous access to the diagnostic information that operators require to safeguard assets. Maintenance policies can be safely amended to increase productivity, for example, relaxing set lubrication schedules and using the monitoring system to signal on-demand maintenance for whichever asset requires attention instead. Through unparalleled access to diagnostic information, resources can be effectively channelled to improve efficiency. With total access available via a combination of smart devices, networking and the use of ‘smart manufacturing’ principles - responses to alarm conditions can be faster, with both production and maintenance teams referring to accurate, predictive ‘live’ information.
Pharmaceutical pressure
As pharmaceutical manufacturers look to boost their productivity and minimise downtime, frequently now with the goal of moving from batch production to continuous operation, the importance of smart condition monitoring technologies is growing.
As a tightly regulated sector with huge financial incentives to keep production lines running, manufacturers in the pharmaceutical industry typically experience less unplanned downtime than those in other sectors. Indeed, pharmaceutical manufacturers can point to fewer hours of unscheduled downtime than the equally high value automotive industry, and fewer also than the similarly regulated food and beverage sector.
This has been the case for some time; surveys conducted as long ago as 2004 by downtime expert Don Fitchett highlighted not only this push for manufacturing excellence within pharmaceuticals, but also pointed out how extensively companies were tracking their downtime, with standardised metrics in place to report it.
This was hardly surprising, though, given that almost 90 per cent of them cited that downtime was either extremely or very important.
However, monitoring unplanned downtime is not the same as preventing it. And the component failures or bottlenecks that are prime causes of downtime can also impact on production line performance and on product quality. Combined with availability, these three key performance indicators are at the heart of measuring Overall Equipment Effectiveness (OEE), as defined by the simple formula: OEE = availability x performance x quality.
Fast forward, then, to today and statistics highlight an average OEE score within the pharmaceutical sector of 60-70 per cent, some way short of the score of 85 per cent that is generally considered as world class. “While the pharmaceutical sector is ahead of the curve in acknowledging and tracking its downtime, it would appear it is not yet truly on top of maximising availability and boosting line performance,” says Neal Welch, life science sales manager, automation systems division at Mitsubishi Electric. “Pharmaceutical manufacturers are acutely aware that they need to increase machine availability and reduce unscheduled downtime to respond to global competition and minimise costs.
“But the traditional techniques for helping to predict downtime to manage maintenance and to help maximise reliable production have typically been either expensive – such as using outsourcing experts to analyse machinery and interpret the results of complex algorithms – or highly subjective, relying on the experience of in-house engineers who are intimate with production lines and can ‘hear’ or ‘feel’ impending component failures.”
The move to continuous production from batch production is another trend in pharma manufacturing that is also creating an environment where production systems are even less tolerant of breakdowns or equipment variability. Traditionally, a drug would be manufactured in stages, with lab tests carried out at each stage to confirm the attributes of the compound in production. Test regulations now, however, allow for real-time testing to be carried out on-machine during a continuous production process. When the production process does not stop, then reliability must be 100 per cent.
Enabling continuous production
SCM can go further, by providing an essential tool to assist the pharmaceutical industry with the move from batch production to continuous production. This shift to continuous production requires increased running time between periods of scheduled maintenance and is dependent upon the ability to reliably monitor the condition of the operation.
“The system addresses this requirement, because, along with indicating a developing problem on a machine or line, it is also able to give meaningful detail about what the problem is and how serious it might be,” adds Welch. “And by providing a complete and holistic overview of the workings of the plant’s assets, it can also enable a model-based fault detection and identification system to be implemented, with an active fault diagnosis framework.
“We can see, then, that SCM offers many benefits to the pharmaceutical sector. It provides reliable monitoring of individual machines and complete production lines, with intelligent process monitoring to deliver a full service built around machine diagnostics. Further, it offers easy installation and intuitive operation, with a system that is readily expandable. Using the ‘smart’ approach, condition monitoring can be easily integrated into the plant system architecture, starting with as much or as little as is required, and growing the system as appropriate to provide the most comprehensive overview.”