Smart maintenance managers do respond faster to equipment or asset failure, but they also think on how to use reduce equipment failure and deliver higher run time for maximum productivity, the ideal way is to plan PM schedules (preventive maintenance) and implement it on timely basis. There are quite lot of challenges doing this manually on MS Excel sheets, maintenance engineers acknowledge that they need cloud base CMMS to plan and control PM Plan / Schedules.
Types of Preventive Maintenance (PM) Schedules
We will try to explain you each of these PM types mentioned above in a lay man’s terms, to begin with you will have to conduct an maintenance or failure review of the asset this is very important and few things need to be taken care while creating a PM plan of the asset/equipment.
As a case study let us take CNC Lathe to set a discussion ahead -
Once the Plan is ready we will break into segments as below shown in the chart, based on the classification we will set PM Schedules in CMMS software which will aid us to follow the set plan by creating timely PM work order notifications for internal and external maintenance teams.
Time base PM Schedules
In a time based preventive maintenance plan (PM), the maintenance tasks are planned and performed depending on the time specific intervals determined, it could be hours or days, typically companies use Day as standard interval for non critical tasks. In the above table serial No. 1, 2 & 3 are time base task to be performed against condition of Meter or Gauge base readings, which ever triggers first, while serial No. 5 task is purely time base.
Meter base PM Schedules
Meter based readings are setup intervals between maintenance on meter reading which is entered by the production team, it could be any unit kg, miles, hours, cycle, etc... say in this case it is hours so the maintenance team has to perform the maintenance task every 250, 500 or 1000 hours as mentioned in Serial task No. 1,2 & 3. The condition mentioned is corresponding to time base, which ever triggers first.
Gauge base PM Schedules
Gauge base measurement also referred as condition base maintenance works when value of entered by production team is higher or lower than the set value, it triggers the PM Work order automatically by comparing to the entered value and reference value set during PM plan, the unit can be anything like Pressure, Temperature, Vibration, Inch, mm, etc.. In this case above the set value in Serial No. 1 & 3 is Lower < +0.25mm & Higher > +0.15mm respectively. The condition mentioned is corresponding to time base & meter base, which ever triggers first.
IoT Sensor base PM Schedules
You can connect various types of sensors to trigger maintenance task set during PM plan, say for example we have connected a Vibration sensor which monitors CNC Machine vibration on regular set interval and transmit data to the CMMS cloud, in serial No. 4 of the above given table we have set the vibration limit at 15 mm/s if the sensor value crosses the threshold it will trigger a PM Work order, the data gathered from the sensor during specific time intervals can be graphically viewed from the data analytics dashboard.
It is not mandatory that you have to create inter-dependent PM triggers, you can also create individual time, meter or gauge base triggers as shown in the above chart. EZmaintain CMMS allows users to set email alerts for external contract /third party maintenance agency, at the same time creates work order on master dashboard for tracking.