A Journey Toward Wireless Asset Condition Monitoring
A Journey Toward Wireless Asset Condition Monitoring
by JBILI Abdenour
"In maintenance, you must always begin from the beginning, but don’t forget to set your ultimate goal. Otherwise, you will just waste your time and energy, and lose your right path."
"Don’t begin with purchasing new devices to enhance the ACM; think first of the right organization and workforce competence and skills to use contently what you will buy."
In maintenance, a big challenge is how to put different concepts and theories into practice, especially when you must also change the mind-set of your workforce and introduce a new way of thinking.
At OCP Group, the world’s leading producer of phosphate rock and phosphoric acid, and a global fertilizer leader serving the agricultural industry, several obstacles surfaced while trying to change its operating point of view in maintenance.
The journey began in 2007 with a mission to conduct systematic overhauls and preventive maintenance based on frequencies and durations. Condition-based maintenance (CBM) was not fully developed at that time and was considered as a luxury, not a necessity. Moreover, people did not really trust the results of CBM.
In 2008, maintenance engineers in the Maroc Chimie plant received basic training in vibration analysis. From this, they began to understand the benefit of vibration analysis to predict and fix future failures before breakdown. It was really a shift in the company’s philosophy of maintenance and really magical to see how basic vibration training can make a huge impact when it is used.
The big question was how to enlist all Maroc Chimie workers to embrace and engage in this new concept. How do you lead a smooth change in maintenance, and even in production, and be more persuasive? The first step was to learn and deeply master all asset condition monitoring (ACM) techniques and methods, especially vibration and infrared temperature measurements, buy and use the right devices, and show and publish results to others.
The first achievement was when a maintenance engineer managed to balance a big blower in a fertilizer plant, which runs with 45 mm/s (0,147 ft/s) in vibration to 2mm/s. Back then, it was an impossible problem to solve in the maintenance workforce’s eyes. One worker remarked: “I know that we can balance blowers, but not this one! How did you do it?” It was then that the maintenance engineer realized the problem was deeper than just exploring new technologies or applying conditional maintenance in the plant. The limitation was in each maintenance worker’s brain and beliefs, which shackle and stop each of them from seeking and exploring new solutions.
To break this barrier, plant maintenance workers needed to gain more confidence in themselves. To become more confident, you have to increase your competence. Competence comes naturally with experience, or with high-level training and practicing. That is why, in 2009, the OCP Safi plant initiated a big effort for ISO certification on vibration and thermography. All Maroc Chimie inspectors were certified ISO level two in those fields. They became proud and more confident in their analysis and interpretations. Then, other maintenance personnel showed more respect and esteem to inspectors and accepted their recommendations.
The first version of the CBM program was in the form of an inspection calendar containing all tasks and frequencies. Inspectors had to check the frequencies from the calendar and do the inspection rounds, then initiate a work order in the computerized maintenance management system (CMMS) if the vibration or temperature exceeded the limit value.
At the end of each week, inspectors would send an overview report of all anomalies detected within the week, with the number of each work order and the investigation or remedy status. Those reports allow the plant to have a reliable database of all previous problems to improve future maintenance strategies.
In 2010, in order to be more professional and share inspector expertise, each work order generated by the inspector was accompanied by an “Anomaly Flash” report, scientifically describing the physical phenomenon in more detail. This document was the last link to complete the chain of the plant’s inspection process and respond clearly to maintenance personnel’s needs and requests.
To better utilize its CMMS, since 2012, all inspectors’ calendars have been configured in the CMMS system and all measurement values were integrated and stored inside. With business intelligent software, the company can generate all graphs and follow measured value tendencies and trends.
You risk regressing if you don't work in continous improvement of your system.
As is the case for all disciplines, when you feel that you master something, be aware! You risk regressing if you don’t work in continuous improvement of your system. It is not something that is “NICE TO HAVE” to make your system living; you must improve or just think deeply in all your maintenance activities to maintain and drive your progress. In the case of Maroc Chimie, new gaps began to appear:
- Retirement of experienced inspectors;
- No respect of the maintenance calendar (e.g., vacation periods, difficulty to access in some equipment at the top of the elevator, breakdown in measurement devices, etc.);
- Disinterest of inspectors in periodic measurements (task without added value), especially when they feel more competent.
In dealing with this situation, the company explored several questions: How can new technologies help us overcome all the previous constraints? How can we make our system less dependent on humans without losing their advantages? After extensive research, the company found the appropriate solution in a wireless system. The concept of this solution is summarized in Figure 1.
Figure 1: Wireless measurement and interpretation
It consists of wireless sensors that send periodic measurements of vibration and temperature through multiple relays to the gateway. All this information is recorded on the server and can be displayed and analyzed on the system’s website. You can also add the spectrum of acceleration, velocity and temporal signal if you want to enhance your analysis.
With this solution, any qualified and experienced inspector can analyze values and share reports. This activity can be outsourced, depending on the company’s maintenance strategy. According to the available number of wireless sensors, you can begin with critical equipment and expand it to others; you also can change the position of the sensors if the criticality of equipment changes. Maroc Chimie outsources this activity to a company that handles the maintenance of all systems and interpretation of results. The plant receives a “daily flash,” which includes the situation of the network and all measured alarms, and a more detailed weekly report with spectrum analysis, efficiency of previous interventions, etc.
Now, the plant is working on a link between this solution and the CMMS to automatically generate a work order if the value exceeds its limit. The calculation of mean time between failures (MTBF) and mean time to repair (MTTR) also can be done automatically using this solution to follow or confirm the reliability of the plant’s equipment (e.g., if the value of vibration is approximate to 0 mm/s, the equipment is at a standstill). The plant just needs to work on a combination of values and information in the wireless software to have the right information.
What’s next? How to make all ACM elements wireless. The plant is now working with several subcontractors and suppliers to develop this aspect. It will test a new wireless oil analysis in a turbine tank. It is also working on intelligent lubrication with wireless sensors, which would automatically add oil or grease if the temperature is high.
The impact of this new way of managing ACM on other Uptime® Elements™ is summarized in Figure 2. The creation of a reliability section and a laboratory of maintenance in the plant facilitates the interaction between wireless systems and other maintenance activities.
Figure 2: Managing ACM on other Uptime Elements