Improve equipment performance and reliability
Many companies engage in reactive maintenance, which is when you wait for a problem to show up and then fix it. But this method can be very expensive due to unplanned downtime. Innovators are now saving millions by switching to a Total Productive Maintenance system to ensure machines run optimally, while using predictive analytics and maintenance techniques to anticipate problems before they occur.
What is Total Productive Maintenance?
Total Productive Maintenance (TPM) is a system designed to stabilize equipment performance and reliability. The primary goals of TPM are to eliminate waste caused by accidents, emergency and unscheduled downtime, defects and speed losses.
TPM achieves this through proactive maintenance and improvement of the integrity of production, safety and quality systems to ensure all equipment is in top working condition, minimizing breakdowns and delays in manufacturing processes.
TPM is successful because it promotes group activities among shop floor team members. The knowledge base received from team members is used to improve equipment reliability and productivity, thereby lowering maintenance and operating costs.
This is achieved by:
Adopting a lifecycle approach to improve the overall performance of production equipment
Improving productivity by highly motivated workers, achieved through job enlargement
Using voluntary small group activities to identify the cause of failure, as well as possible plant and equipment modification
The Eight Pillars of TPM
Autonomous maintenance
Routine maintenance, such as cleaning, lubrication and inspection, is performed by the machine operator.
Focused improvement
Creating a voluntary small group to identify the cause of failure, as well as possible plant and equipment modification.
Planned maintenance
Data-driven maintenance schedule using prediction and failure rates.
Quality management
Creating production processes to detect and prevent errors.
Early equipment management
Designing new equipment based on knowledge and understanding gained through TPM program.
Education and training
Train and educate operators, maintenance and managers on necessary information to achieve TPM goals.
Administrative and office
Seek ways to apply TPM to administrative and office functions.
Safety, health and environmental conditions
Ongoing maintenance of a safe and healthy workplace.
Total Productive Maintenance Types
TPM combines three different types of maintenance, including autonomous maintenance, preventive maintenance, and early equipment maintenance. Each plays an essential role in a TPM program:
Autonomous maintenance
Determines what maintenance tasks, adjustments or cleaning can be completed by operators due to their daily use of the equipment and knowledge of when a machine acts differently.
Preventive Maintenance
Seeks ways to prevent the need for maintenance and introduce methods to monitor the critical areas that require attention in real-time.
Early equipment maintenance
Strives to ensure all possible components are no/low maintenance through the design, specification or build of your equipment.
Overall Equipment Effectiveness
Increasing the Overall Equipment Effectiveness (OEE) is a top priority of a TPM system. Autonomous maintenance uses OEE to measure losses and the opportunity for improvements by defining:
The percentage of time a machine was producing quality parts compared to the time it was planned to be producing quality parts
The equipment’s actual productivity compared to the ideal productivity, during a specified time
The difference between actual performance and ideal performance is waste, which TPM seeks to eliminate.
Three Factors of OEE Metrics
The OEE metric can help you develop a clear, cohesive plan of attack for achieving your TPM goals. It includes three factors — availability rate, efficiency rate and quality rate.
Availability rate
Availability rate helps you evaluate how much unplanned downtime you experience because of machine breakdowns or product changeover. When evaluating factory capacity, it’s essential to remove any time allotted for planned maintenance activities that are a part of your preventive maintenance program.
For example, if you have a line that runs 60 hours, and it takes three hours to complete the weekly preventive maintenance, then the equipment is available for 57 hours. When you schedule the weekly production, you must use the 57 hours of availability instead of the 60 hours worked by operators. The preventive maintenance activities remove 5% of the equipment time from the operator. As a plant manager, you can see why it might be tempting to “put-off” the preventive maintenance and just run the equipment to failure.
Efficiency rate — performance
Efficiency or productivity rate evaluates how much you are idling or stopping the machine, or running at reduced speeds. It’s usually one of the hardest components to identify and correct because identified issues tend to require an all-out blitz to restore the condition to standard.
When your equipment goes down, your maintenance people scramble to get the machine running again. When you have a quality issue, your quality and production people scramble to correct the situation to begin producing good parts. However, when you are running below “nameplate” speed, or you idle the machine, it can just look like a part of the process.
It’s always important to remember that what may be considered standard may be a hidden issue. When stoppages or reduced speed become a normal part of the process, it’s time to use structured problem solving to investigate all of the potential causes for the idling/stoppages and reduced speed.
Quality rate
Quality rate evaluates the level of scrap and rework. In many situations, scrap is considered just a part of how the machine works.
Once again, the quality rate provides the opportunity to use structured problem solving to investigate the potential causes of scrap and rework. When seeking out the causes, it’s important to carefully determine which issues have become accepted as part of running the machine. When there are high levels of rework, there’s a capacity loss across the equipment for “good first-time” parts.
Ideally, to get the complete picture of how a machine runs, you should measure first-pass yield and scrap together.
To continue reading this article in its entirety and learn about the direct and indirect benefits of Total Productive Maintenance, click here.
Previously Featured on Brady's Resource Center.