November 16, 2020By Peter Philips
Preventive and predictive maintenance are two important elements of any equipment maintenance program.
Photo: Denys Yelmanov / Getty Images.
Considering PM activities make up approximately 70 to 80 per cent of our time, it only makes sense that those hours are spent wisely, as the effort put into PM activities directly affects equipment reliability. Poorly written and executed PMs can easily be identified as seen through unplanned equipment downtime and decreased equipment availability.
As equipment becomes more complicated, the days of generic PM instructions and leaving equipment maintenance to the discretion of tradesperson has long passed. People maintaining the equipment need specific guidance to perform effective PMs that leaves nothing overlooked due to lack of detailed instructions. Therefore, bullet proof PM regimes need to be developed to improve and maintain equipment performance.
What exactly is a PM Regime? They are detailed PM programs that include all necessary documentation, resources, skills, and knowledge needed to perform specific and detailed preventive maintenance on a single piece of equipment. There are three key PM regimes that need to be developed.
Lubrication PM regime
A properly developed lubrication program determines the specific type of lubricant to use, and when and how to apply it. Well-designed lube programs ensure the proper lubrication frequencies, type of lube, and the amount and method of application, to ensure equipment does not fail due to the lack of lubrication. However, there is more to a lubrication program than just applying lubricants. They need to be stored and handled properly to prevent contamination, from the time they enter the facility until applied to the equipment. Lubrication storage areas need to be organized and clean to protect the lubrication products while they wait to be used.
An effective lubrication PM regime needs to include
• Storage and handling procedures for all lubricants;
• Stocking the right lubricants prescribed by the equipment manufacturer;
• A lubrication plan and map that includes the instructions of when to lube, where to lube, amount to apply, and how to apply it; and,
• Lubrication training for all trades people and equipment operators.
Time Based Preventive Maintenance Regimes
Every piece of equipment requires inspection to evaluate the state of its wear components. Mechanical drives, belts, chains, and gearboxes, need periodic inspections. They need to be written with the appropriate information to ensure the equipment is reliable between scheduled inspections. Often, it is assumed that tradespeople, because they are trained and certified as industrial mechanics and electricians, know everything about their profession.
This is far from the truth. People are trained on the basics, and over years of instruction and experience they learn how to be good at what they do. Tradespeople cannot be expected to know about every piece of equipment and its specific maintenance needs. Tradespeople need training and specific instructions to objectively evaluate and maintain the health of the equipment.
Time-based PM regimes need to include
• Specific and detailed equipment inspection list that include manufacturer recommendations, and plant equipment knowledge;
• Documents, SMPs, and specific equipment details available during inspections, component replacement, and rebuilds;
• Wear components stocked in the storeroom;
• Continuous review of the PM program;
• Monthly equipment reliability reports to determine the effectiveness of the regime; and,
• Periodic training for tradespeople and operators on new equipment and maintenance best practices.
Predictive maintenance regimes
Equipment that falls into the category of critical or hard to access, usually get special maintenance attention and evaluation using technology. Condition-based monitoring has come a long way in recent years, and the availability of cost-effective solutions have made this technology more attractive and affordable. In the past, we have depended on technicians, internal or external, to take periodic condition monitoring readings, and then waiting for the analysis. This type of monitoring is quickly being replaced with permanently mounted sensors on the equipment that provide continuous readings and analysis of the equipment’s health and performance. There are several vendors that specialize in remote sensing and are willing to assist with installation, set up, and analysis.
Other technology such as machine learning and Internet of Things (IoT), is changing how condition monitoring and predictive tools are used to sustain equipment reliability. Industry and Maintenance 4.0 implementations are gaining favour in plants around the world and include maintenance technologies that are vastly improving equipment reliability.
Predictive maintenance regimes need to include
• Selecting the equipment to use equipment monitoring;
• Partnerships with remote condition monitoring vendors;
• Removal of redundant time-based maintenance tasks from the maintenance schedule (CMMS); and,
• Training of staff on new monitoring technologies.
Considerable time, effort, and cost are associated in the development of ironclad PM regimes. They need to be planned and executed on time, because backlogged PM regime work orders will jeopardize the results, and the regimes will start to crumble. In most manufacturing plants, PM hours outweigh the number of available labour hours and equipment availability to perform PM regimes.
Therefore, the design of the PM regimes must take these constraints into consideration. Apply estimated hours to every PM regime and develop the PM program based on available time and resources. Effective regimes encourages smarter maintenance planning and execution, because missed or poorly done PMs directly affect reliability.
To be successful with effective PM regimes
• Choose the right combination of PM regimes for the equipment;
• Match PM regime required hours with available resources;
• Develop specific detailed regimes for each type of equipment;
• Maintain the necessary parts and resources to complete the regime;
• Train people to understand their responsibilities and how to perform the PM regime; and,
• Measure the change in reliability using monthly graphs and KPIs.
PM regimes that are properly developed and executed are now a best practice in every manufacturing plant wanting a higher percentage of equipment availability. Breakdowns may still occur, but at significantly less frequency, and repair times will fall dramatically, and more time can be spent on
PM regimes. MRO