Preventive maintenance actions can be generated according to certain conditions of an object. In order to control preventive maintenance actions in this way, you should define appropriate parameters for the object. Next, you decide which of the parameters are to be used as criteria for generating PM actions. Finally, you take and register measurements for those parameters.
There are two types of parameters: cumulative and limit values. When a measurement of a parameter falls outside the specified limit values, or the cumulative value exceeds the limit for generation, a PM action is generated. One example of a parameter with limit values is temperature; a cumulative parameter could be operating time. When two or more cumulative measurements are registered, it generates a condition based forecast PM plan. If several measurements are entered for a parameter that may result in an unrealistic forecast plan compared with the start value and interval on the PM action, there is a mechanism to prevent generating more than one maintenance plan line on the same planned date.
IMPORTANT: Upon registering accumulated measurements, the condition based forecast PM plan will be regenerated accordingly. The user can choose to run the regeneration as a background job by setting the system parameter PM_CON_PLAN_SYNC to BATCH. The Plan Out of Sync flag in the PM Action/Condition tab will indicate if the condition based forecast PM plan is in conflict with the latest measurement entered for the object. When the condition based forecast PM plan is in conflict, it will not be allowed to generate Work Orders from the affected PM Action. If the parameter PM_CON_PLAN_SYNC is set to ONLINE, the regenerate plan process will run immediately, and this might take a few minutes.
See the chain of events for condition-based PM in the figure below.
The chain of events for condition-based PM actions.