One of the most common performance metrics is planned vs. unplanned work orders. The benchmark goal has been 90 percent planned (preventive maintenance and other planned activities) and 10 percent unplanned corrective/breakdown maintenance. In reality, with most organizations the ratio is anywhere from 10 to 30 percent planned maintenance to 90 to 70 percent unplanned. This is indicative of operating in a reactive mode, which contributes to waste, reduced equipment life and lost productivity.
A thorough understanding and analysis of a maintenance work process flow makes it easier to identify and eliminate waste. The goal is not only to eliminate waste but to develop an improved work process flow that is more effective and productive. As the flow is thoroughly reviewed and analyzed, the entire process flow becomes visible and wasteful activities such as delays, unnecessary travel and the like are easily identified.
Following are some ways to minimize wasteful activities:
Condition monitoring usually involves the use of installed devices (gauges, meters, etc.) to monitor the operating conditions of equipment and other assets. An example is pressure and temperature readings on a boiler. Maintenance can establish operating limits for the condition(s) being monitored and trend the observed data. If the observed data is outside of a certain predefined range of values, some maintenance action may be required. This is referred to as condition-based maintenance. It can be very effective and less expensive than periodic or fixed frequency maintenance.
The planner/scheduler’s role is very important in a lean maintenance environment. The goal is to optimize utilization of available resources. Detailed job plans should be developed for all approved open work orders including:
Delays must be avoided at all cost. Weekly scheduling must be done with daily fine tuning as necessary. This level of detail and coordination is required to achieve a lean and efficient maintenance operation.
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