Planned preventive maintenance (PPM), more commonly referred to as simply planned maintenance (PM) or scheduled maintenance, or any other acronym referring to Preventive Maintenance is any variety of scheduled tasks, routines, lubrications, inspections and adjustment on a set frequency. The scheduled visit is typically done by a maintenance technician with a skill set sufficient to do the visit and complete some pre-defined list with the result being that the equipment, item on a piece of equipment or device attached to a process is operating within certain parameters, the result being to ensure that unscheduled breakdown, shutdown for emergency repairs, or deviation from design throughput and quality is avoided.
SOMAX allows for these inspections to be done in multiple different ways, with multiple different results.
Calendar Based Last Due Scheduling - Most rigid application of calendar scheduling as it applies to Preventive Maintenance. Simply put, the user determines a frequency in days, date of the month, and number of months, or day of the week, and number of months and the Work Order Generation when run by the user with locate and generate all necessary tasks, lubrications and inspections that have been defined by the user, build the necessary Preventive Maintenance work order, assign the work order to the predefined technician, including all attachments, transferring the work order to the work order scheduled table.
- The preconceived advantage by some users of this process is that a Preventive Maintenance schedule will NEVER be missed or allowed to lapse.
- The disadvantage to this process, many duplicate work orders will be generated and maintenance management will not be as proactive in monitoring Overdue Work Orders.
Calendar Based Last Done Scheduling - Less rigid application of calendar scheduling as it applies to Preventive Maintenance. Simply put, the user determines a frequency in days, date of the month, and number of months, or day of the week, and number of months and the Work Order Generation when run by the user will locate and generate all necessary tasks, lubrications and inspections that have been defined by the user. The difference between Last Due and Last Done at this point, the system will check to see if the last Generated Work order based on the frequencies has been completed, if not the system stops and ignores the schedule moving on to the next schedule until a record is found that has been completed. At this point the system will build the necessary Preventive Maintenance work order, assign the work order to the predefined technician, including all attachments, transferring the work order to the work order scheduled table.
- The advantage this process is that a Preventive Maintenance schedule will only generate necessary uncompleted work, and duplicate work orders will NEVER be generated.
- The disadvantage to this process is that management MUST monitor the Overdue Work Orders to be proactive insuring that sensitive Preventive Maintenance work does not be seriously overdue.
Both process’s advantages are:
- Easier for planning the system does all the scheduling, if spares are attached to the process ordering is simplified
- Costs are distributed evenly, and it is easy for management to determine labor requirements whether right or wrong. Preventive Maintenance labor leveling can be accomplished
- There are no initial startup costs for instrumentation, I.O.T devices, networking or PLC driven supervision of equipment.
Both process’s Disadvantages are:
- Less reliable due to skill level differences and honesty of input.
- Less reliable than PLC fact based fault reporting
- Highest cost maintenance due to excessive lubricant usage, frequent parts change out and replacement of non-failed parts
- High training and labor costs, Preventive maintenance is done non-dependent of requirement.