Supply chain
Monitoring equipment setup is complicated process
Chloe Liao, Taipei; Rodney Chan, DIGITIMES

With advancing Industry 4.0 developments, large-scale enterprises generally have no problem putting equipment monitoring in place, which can be handled simply by their own automation departments. However, to small-scale manufacturers not as resourceful, implementing equipment monitoring can be challenging.

Predictive and preventive maintenance - an important concept of equipment monitoring - is essential to Industry 4.0 manufacturing. It prevents production shutdown due to unexpected equipment failure or extra costs incurred from unnecessary early replacement of good parts.

Large-scale manufacturers, such as TSMC, had already put the concept of predictive and preventive maintenance into practice long before equipment monitoring was widely embraced. They have devoted R&D resources and amassed considerable knowledge and expertise in this respect.

The market is already seeing a wide variety of equipment monitoring solutions. The availability of total solutions integrating hardware and software implementations has lowered the threshold for manufacturers to introduce equipment monitoring systems at their factories. Advantech's equipment condition monitoring software WebAccess/MCM, NEXCOM's predictive maintenance system solution and NI's machine condition monitoring (MCM) solution are examples of complete services combining the installation of hardware and software systems and the provision of professional analyses.

There are generally two types of manufacturers that have needs for equipment monitoring systems - large enterprises with strong technical capabilitie, and businesses with limited resources. In-house engineers of large-scale companies bring in equipment monitoring systems mainly for the purpose of accelerating development cycle. Less resourceful businesses only now trying to catch up with the equipment monitoring trend do not have employees with the required system development skills or specialized data analytic expertise.

Industry 4.0 needs vertical integrations between upstream and downstream industries. An attempt to introduce any new technology can be a whole new challenge to the manufacturer making the move. In view of this, equipment monitoring solution providers have developed ready-to-use software packages to help manufacturers significantly cut down R&D and labor costs. Alternatively, they provide user-friendly graphical interface so that users can quickly learn the system and be able to focus more efforts on studying the signals.

Shen-Wei Wu, product manager, Industrial IoT Group, Advantech, indicated a total solution allows users not specialized in equipment data collection and analysis to also be able to put a basic monitoring solution in place without problem. This saves time in the process of installing the system. Some software packages even come with built-in basic data compilation and diagnostic functions, such as time domain and frequency analyses as well as filter data averaging. This is exactly what businesses with no data analysis experts need.

On-site experts play a critical role

A total equipment monitoring solution lowers the technological barrier for the initial introduction as it offers users flexible development tools. However, the real challenge is how to process and analyze the physical signals generated from the operating equipment and convert them into practical and useful information to help customers carry out predictive and preventive maintenance. Signal analysis is easier said than done.

To accurately analyze diverse physical signals, manufacturers will need help from on-site experts who are familiar with equipment characteristics. The role of on-site experts is similar to that of veteran technicians in the old days. Aside from helping manufacturers raise the efficiency during the process of hardware set-up, on-site experts can also help increase the accuracy of irregularity detection during the process of model building.

Citing a case at a factory, Wu found that model building is usually the most time-consuming step during the initial set-up of an equipment monitoring system. This is because the equipment has to maintain non-stop operation until an irregularity occurs so that there are parameters available for analysis and comparison. This can take up to one month or even one year.

The process of model building is like a self-learning process for the equipment. By simulating occurrences of irregularity, the equipment monitoring system is trained to make a determination on the cause of irregularity through changes in the physical signals and then proceed to resolve the issue. With a growingly large database of physical signals for analysis and comparison, the accuracy on irregularity determination will significantly increase.

Although model building takes time, once you get the ball rolling and successfully get past this stage, all that remains is to follow standard procedures and put the module to work in other pieces of equipment. Subsequent development cycles can then be accelerated. Model building is an essential and intricate step in the set-up of an equipment monitoring system, which cannot be handled by general factory workers.

This is why on-site experts can be of help at this stage with data analyses and system configurations based on the structures and characteristics of the mechanical components and the signals generated during operation. The purpose of engaging on-site experts is to ensure manufacturers can quickly build up an accurate model at the beginning of system set-up to protect manufacturers from having to spend more time correcting errors made in the process.

Find the best suited monitoring system for individual industry

Hardware configuration is also an importation consideration in the build-up of an equipment monitoring system in addition to signal analysis and processing. The selection of monitoring devices will also differ based on the manufacturer's requirements, with cost being one deciding factor and business type being the top consideration.

Take Advantech's signal capture card for vibration measurement for example. A range of signal capture cards are available to meet the needs of different industries. The main differences are in their ability to simultaneously measure multiple sets of signals as well as their resolution levels. Signal capture cards supporting a higher resolution can detect finer vibration frequencies.

Whether simultaneous capture of equipment signals is achievable depends on the sampling frequency and availability of independent channels. Sampling frequency refers to the number of physical signals collected per second. A higher frequency means more samples are captured, which also means more data entries are available for time domain and frequency domain analyses to arrive at accurate judgement. Channel independence allows each channel to be able to collect data independently at the same time.

In contrast to sampling frequency, resolution, which defines the fineness of signal changes that can be captured, is another factor that affects monitoring efficacy. Signal capture cards supporting a higher resolution can capture finer changes in the collected physical signals and therefore can detect very subtle vibration changes.

Manufacturers in the machine tool industry are generally satisfied if an equipment monitoring system can give them enough time to take preventive actions before failure occurs, thus imposing less stringent requirements on the sampling frequency and resolution. They tend to adopt entry-level low-cost systems to meet their needs. To the semiconductor industry, however, it's a different story.

Semiconductor manufacturing lines produce electronic devices with high precision and have to maintain operation around the clock. Unlike machine tools that perform cutting on large-size work pieces, semiconductor manufacturing allows little tolerance for slight deviations so manufacturers in this field of work place great emphasis on instantaneity and synchronization in their selection of monitoring systems. They tend to opt for signal capture cards capable of simultaneously collecting signals so as to prevent misjudgment due to latency.

According to Wu, the composition complexity of production equipment is proportional to its level of precision. A piece of sophisticated equipment will generate multiple vibration frequencies during operation. Even minor vibrations from a tiny component could be the cause of equipment irregularity. Therefore, high-precision production equipment such as that used in semiconductor manufacturing requires high sensitivity detection of every subtle vibration signal, which calls for signal capture cards supporting high resolutions.

However, a higher end monitoring system does not necessarily offer better signal detection sensitivity. Manufacturers should still choose a monitoring system best suited to their needs. Cost consideration remains the deciding factor when Taiwan industries make their choice on equipment monitoring systems. High-end systems will certainly cost more. Manufacturers will have to weigh the expense against the benefit and decide whether to make such an investment.

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