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Preventive maintenance (also called planned maintenance or planned preventive maintenance) is driven by time, meter or event based triggering. Maintenance tasks that are undertaken during PM’s are pre-determined based on a number of factors including experience, age, manufacturers recommendations etc. It is assumed that a machine component will degrade within a time period that is common for its type. Under a preventive management approach, the relevant parts will be removed, replaced or rebuilt on or before the expected failure point. For example, your engine oil in your car is proactively replaced at 10,000 miles. Mean-time-between-failure (MTBF) statistics can determine help optimize preventive maintenance management schedule to include inspections, repairs and rebuilds.
The main issue with a preventive maintenance approach is that the way a machine is used, how often it is used, as well as a number of other variables, directly impact the operating life of the machine and its components. In many cases, parts are replaced when there is no need. Therefore, this approach can sometimes result in unnecessary maintenance. Unnecessary maintenance can become even more costly if the technician causes collateral damage during the replacement.
Predictive maintenancePredictive maintenance is determined by the condition of equipment rather average or expected life statistics. Essentially, this methodology tries to predict the failure before it actually happens by directly monitoring the machine during normal operating condition. In the car example above, rather than replacing the oil every 10,000 miles, using predictive maintenance methodology, oil samples are taken at regular intervals and the oil is replaced when it degrades beyond a certain point. This is called condition-based maintenance. In many cases, when predictive analysis spots an issue, the repair can be scheduled at a time that minimizes the impact on production.
A range of cost-effective tools can be used within a predictive maintenance program to analyze system performance and produce accurate factual data about pivotal systems, so that maintenance activities can be undertaken the moment they are needed. Improvements in quality, profitability and productivity can result when predictive maintenance is used on capital-intensive assets.
Effective maintenance managementMany businesses are surprised to learn that significant maintenance dollars can be saved through the use of effective maintenance management methods in the right places. The impact of random or inappropriate maintenance can certainly be felt in terms of the quality of products and services, operating costs and thus the bottom line so it makes sense to select the appropriate policy for each asset.
The great news for businesses is that Maintenance Assistant CMMS offers a way for a business to enhance the effectiveness of its maintenance procedures and processes. It can be used to track both preventive and predictive maintenance in one CMMS. For example, the scheduled maintenance time based trigger can be used to track time-based preventive maintenance or time based predictive inspections for CBM. In a recent post, Jeff O’Brien outlined how to integrate Condition Based Maintenance with MA CMMS. With the API under development and due for release in 2014, it will be possible to integrate systems directly with the CMMS so they can communicate directly.
Predictive Maintenance:
It pursues constantly know and report the status and operational capacity of the installations by knowing the values of certain variables, which represent such state and operational ability. To apply this maintenance, it is necessary to identify physical variables (temperature, vibration, power consumption, etc.). Which variation is indicative of problems that may be appearing on the equipment. This maintenance it is the most technical, since it requires advanced technical resources, and at times of strong mathematical, physical and / or technical knowledge.
Periodic maintenance Time Based Maintenance TBM):
the basic maintenance of equipment made by the users of it. It consists of a series of elementary tasks (data collections, visual inspections, cleaning, lubrication, retightening screws,…) for which no extensive training is necessary, but perhaps only a brief training. This type of maintenance is the based on TPM (Total Productive Maintenance).
periodic maintenance is time based maintenance consists of inspection ,cleaning,servicing...predictive maintenance is based on predicted inspection,diagonise and in order to life of parts
A periodic (Preventive) Maintenance is a routine type maintenance that is performed on time basis (daily, weekly, etc .. ) or on meters and that is mostly needed to check systems and make sure they are working properly. However Predictive maintenance is embedded within the Preventive maintenance as for checking the state of the equipment and evaluate it's life span and act according to that state.
periodic maintenance to do some regular maintenance at certain periods recommended by the manufacturers but predictive to do previous maintenance steps to prevent failure for the system while oepration
Periodic maintenance involves regular checks of the machine working, over a determined period. While predictive maintenance, instead of regular checks, gives emphasis to indications from analysis and observations on the machine to determine whether maintenance is due. Thus the latter takes much less time, effort and expenditure. But it does not complement the entire maintenance procedure. Periodic checks are just as important for predicting deterioration of machinery and providing data to carry out predictive maintenance.
• While both preventive and predictive maintenance have the same objective of preventing any losses to the company and to keep the plant and machinery running in top condition, they differ in approach and requirements
• Preventive maintenance is carried out at regular intervals whereas predictive maintenance is based upon the condition of the equipment that needs to be monitored all the time
• Preventive maintenance is carried out when the machinery is in the shut down condition while predictive maintenance is done with the plant in running condition
• Predictive maintenance relies heavily on information and its correct interpretation
Periodic is calender based or hourly based maintenance.
Predictive is based on Machinery symptom.
Preventive and predictive maintenance are both proactive methods of conducting maintenance within a Reliability-Centered Maintenance routine. This means you're focused on conducting maintenance before there's a problem for both cases. Preventive maintenance Or planned/scheduled maintenance is the most common method of conducting routine maintenance. For all maintenance actions based on a calendar or routine system, technicians are conducting preventive maintenance such as changing the oil, replacing a part or ordering new equipment to prevent a break-down. Pros: Establishes a routine for meeting minimum/maximum standards, extends equipment life time, alleviates workplace pressure. Cons: Repairs are often conducted before necessary, technicians may create additional problems during disassembly. Predictive maintenance Relies on conducting maintenance based on trends within equipment data. This technology is tied to condition-based monitoring systems for reading the output (condition) of an asset’s variables. For example: If a piece of equipment has had temperatures continually rise, an alert or work order for predictive maintenance will trigger before equipment failure. Predictive maintenance is based on predicting when an asset needs attention rather than simply replacing a part when it could have lasted longer. Pros: Full view on expenses including forecasts, prevents unnecessary procedures, helps accurately balance labor and inventory levels. Cons: Expensive upfront costs, not for small companies, not for all industries. As predictive technology develops, some vendors are applying various upgrades to their solutions, while others consider the technology unnecessary and only offer preventive features.
periodic maintenance is to maintain the condition of the machine while the predictive maintenance is like a preventive maintenance to help determine the condition of the machine.
