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Hello, and welcome back to Maximo Bite Size. A series of videos on the functional aspects of Maximo Manage.

Title

Good morning and welcome to the ninth episode in the series on Maintenance Planning and the second of three videos where we explore the functionality of the Preventive Maintenance application. I’m Andrew Jeffery and today we will discuss Meter-based Preventive Maintenance and PM Hierarchies. Next week it will be PM forecasting.

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Learning Objectives

This is the second video on Preventive Maintenance and today we’ll extend our knowledge into meter-based PMs, including a little discussion on what happens when you combine time and meter-based frequencies. We will then follow this with a look at PM hierarchies and what triggers the creation of a work order whether time, meter, or a combination of both. If you have not watched the first video on Preventive Maintenance, then this will be a good starting point. 

Meter-based PMs are more complex to understand than time-based PMs, so you may want to pause the video frequently and use the transcripts and slides that can be found on maximosecrets.com. 

Let’s get started.

Meter Based PM

On the Frequency tab of the Preventive Maintenance application there are two other tabs for Time Based Frequency and Meter Based Frequency , our initial focus will be on meter-based when there is no time frequency set up. You can have multiple meters , these must be of type CONTINUOUS, and they must exist for the Asset or Location referenced on the main PM tab. Meter-based PMs will not work for a Route or a PM based on a GL Account, for this to work Maximo must be able to find the meter readings, which is why either a Location or Asset must be referenced on the PM.

The location or asset meter does not need to be active for you to set up the PM, so you can set things up before commissioning the asset. The frequency defaults to zero , but it must be a positive value to save the record.

For meter-based PMs you’ll find that the calculation of the Estimated Next Due Date is dependent on the meter readings that you enter, both the meter value and the meter reading date, and it is also based on the Average Units/Day of that meter , whether it is being calculated through one of the three methods or the Average Calculation Method is of type STATIC, and it is then an entered value. For meter-based PMs to be effective you need to regularly record meter readings, if you are not prepared to do this then use time-based PMs. Many clients have a Round which is performed on a regular basis, sometimes daily, a Round is a combination of a visual inspection and taking meter readings across the plant or a unit.

The Units to Go field which you can just see is calculated when a meter reading is recorded. It is calculated by subtracting the Life To Date for Asset and the Generate WO Ahead By values from the Next Meter Reading value. The Next Meter Reading is the point at which a work order will normally be generated, the Life To Date for Asset is the accumulated total meter reading for the asset and the Generate WO Ahead By is a tolerance value that allows you to generate the work order a bit earlier, normally used to reflect how many units will be consumed in the time it takes to assemble the tools and materials/services required to perform the work. As the tolerance is in the units of the meter it pays to regularly review this value especially if the Average Units/Day fluctuates over time.

Incidentally, the Estimated Next Due Date (DATEOFNEXTWO) on the PMMETER object is a non-persistent field which will be calculated regularly. This is different to Time Based Frequency where the Estimated Next Due Date (NEXTDATE) is a persistent field found on the PM object. The Life To Date (LIFETODATE) and Average Units/Day (AVERAGE) values will be found on the asset and location meter objects, ASSETMETER and LOCATIONMETER respectively.

Meter Based PM – Fixed or Floating

Meter based PMs support both fixed schedules and floating schedules. When the ‘Use Last Work Order’s Start Date to Calculate Next Due Date’ is set (1) it is a fixed schedule, when it is not set (0) it is a floating schedule. If we remind ourselves of what this means for time-based PMs, for a fixed schedule Maximo uses the Last Start Date field on the PM to determine the Estimated Next Due Date, this is the target start date of the last generated PM work order. For a floating schedule Maximo uses the Last Completion Date field which is the actual finish date on the last generated PM work order.

It is worth noting that once a work order has been generated from a PM the meter readings that subsequently occur for the asset or location play no part in that work order. It is also worth noting that for a fixed schedule PM or a floating schedule PM you would see no difference if you inspected their work orders. Once the work order is generated then any meter readings will only affect the PM and when the next work order is generated. Therefore, there is little point generating work orders in advance for meter-based PMs although when it is a fixed schedule this is possible. The work orders would be generated based on the latest Average Units/Day and not on a future average, which of course remains unknown.

For meter-based PMs on a fixed schedule the Last Start Date is compared with the last meter reading date. If the Last Start Date is greater than the last meter reading date then it is used, otherwise today’s date is used as the date that helps to determine the Estimated Next Due Date . Whichever date is derived the Estimated Next Due Date is calculated from this date using the value of a field called Units to Go divided by the Average Units/Day for the meter.

For meter-based PMs on a floating schedule the Last Completion Date is compared with the last meter reading date. If the Last Completion Date is greater than the last meter reading date then it is used, otherwise the last meter reading date is used as the date that helps to determine the Estimated Next Due Date. Again, the date derived is used with the Units to Go divided by the Average Units/Day for the meter.

A Fixed Schedule allows you to create work orders in advanced, so you could create all the work orders for the year, and this works also for meter-based PMs. If the Average Units/Day is 10 and the frequency is 70 then a work order is generated once every 7 days. This sounds like a time-based PM and although it is meter based it is using the frequency divided by the average units/day to determine a date on which to generate work orders. Therefore, if you are going to generate work orders far in advance which you can only do for Fixed Schedules then you might as well be using a Time Based PM. 

By generating work orders in advance, you are not allowing a change in the average units/day of the meter to ever have an effect. The Units to Go will reduce as you make meter readings. But a fixed schedule is going to ignore when the last meter reading took place and instead use today’s date. This is because Maximo cannot assume there were any units used between the last meter reading date and today. If units were used (but you didn’t have a meter reading) then for a fixed schedule the Estimated Next Due Date is always going to be greater than it might have been if you had just submitted a meter reading. 

Consequently, it is better for meter-based PMs to be based on a floating schedule and this is dependent on prompt completion of the work order and ideally taking a meter reading immediately prior to completing that work order.

Meter Based PM – Setup

A few quick points on what additional steps you need to take when setting up a meter-based PM in addition to what you would do for a time based PM.

For a new asset you have no history of meter readings to derive an Average Units/Day. Therefore, when the asset meter is created in the Assets application the Average Calculation Method should be set to STATIC and a value given for the Average Units/Day field . If you are taking on an existing asset you probably still want to have a STATIC setting for the Average Units/Day initially, but you should also enter the Last Reading, Last Reading Date and optionally the Last Reading Inspector and Remarks fields. The reading you enter as you create the asset meter sets the initial value for Life to Date for Asset. The same applies to the creation of a Location Meter.

It is possible to enter historical meter readings if you are creating an existing asset and the maintenance history is known. In the Assets application use the action Enter Meter Readings and if you make a mistake, you can correct it using the Manage Meter Reading History action. If the meter reading history are actual values, then the Delta field should not be set, it is easy to miss this especially if you were aiming to record Delta values in the future.

When setting up the Meter Based Frequency records in the Preventive Maintenance application you should set the Meter Reading and Meter Reading Date field in the Last Work Order Information section. This is the meter reading when the last work order would have been completed. If these fields are left blank, then the Next Meter Reading value will be set the same as the Frequency which may not be correct if this is an existing asset where there is already a positive meter reading. Setting these fields influences the Units to Go and Estimated Next Due Date. Sometimes when you receive an existing asset you know that it was recently serviced, or your organisation serviced it when it was received. If you don’t know when the asset was last serviced, you can enter any positive value (or zero) to try and set a Units to Go Value that makes sense. 

If you are using Job Plan Sequences, then you should use the action Set PM Counter so that the record with the highest sequence number will be generated when you want it to. This is the same as for Time-Based Frequencies.

When you start generating work orders in Maximo for the Preventive Maintenance record then you will find that the Last Work Order Information fields on the PM Meter record will be read-only. They can be adjusted by using the ‘Set Reading At Last WO’ action and entering a New Reading value.

Note. The ‘Life to Date for Asset’ and the ‘Life to Date for Location’ fields can only be set when you create a meter for an asset or location, if you make a mistake delete the asset meter record before you enter any meter readings. Do not use the Reset/Replace Meters action which also has fields for Last Reading, Last Reading Date and Last Reading Inspector as this is used if you need to replace the meter, it will create a meter reading. Once there are multiple meter readings the asset meter can no longer be deleted you will receive the error ‘BMXAA2884E – Cannot delete assetmeter ODOM-M because it already has more than one meter reading in the METERREADING table.’ The ‘Life to Date for Asset’ and the ‘Life to Date for Location’ fields are the accumulated total meter readings on the asset or location, and they can only be set initially when you create the asset or location meter.

Meter Based PM – Use Actual Reading

There are two fields in the Work Order Generation Information to the right of ‘Use Last Start Date to Calculate Next Due Date’. The ‘Generate Work Order Based on Meter Readings (Do Not Estimate)?’ field will use the actual meter readings and a work order can be generated when an actual meter reading has caused the Units to Go field to reach zero or a negative value. The ‘Generate Work Order When Meter Frequency is Reached?’ can only be set when the previous field is set, and this automatically generates the work order when the Units to Go has reached zero or a negative. Both fields will remain read-only until you have entered a meter in the Meter Based Frequency tab.

When ‘Generate Work Order Based on Meter Readings (Do Not Estimate)?’ is not set Maximo uses the Estimated Next Due Date field to determine whether a work order can be generated. If this is in the future then the Slack Time is added to today’s date, and if this is greater than the Estimated Next Due Date then a work order will be generated. The Slack Time is the field called ‘Generate WOs Due Today Plus This Number of Days’ in the Generate Work Orders dialog. When not set Maximo is using the Estimated Next Due Date, a field that is an estimate of when the Units To Go will become zero using the Average Units/Day of the meter.

When ‘Generate Work Order Based on Meter Readings (Do Not Estimate)?’ is set Maximo uses the Units to Go value to determine whether a work order can be generated. The Estimated Next Due Date is ignored, and the Slack Time in the Generate Work Orders dialog will have no effect. The Units to Go value becomes zero or negative based on an actual meter reading.

These fields would be used with a Floating Schedule where the last meter reading is being used to derive an Estimated Next Due Date. They can be used when ‘Use Last Start Date to Calculate Next Due Date’ is set, a Fixed Schedule, but I do not believe it makes sense to do so because the Estimated Next Due Date is then being calculated using today’s date not the meter reading. 

When ‘Generate Work Order Based on Meter Readings (Do Not Estimate)?’ is set the Estimated Next Due Date is the projection of when the Average Units/Day will reach zero from the latest meter reading, this may be in the past but still no work order will be generated. When Units to Go reaches zero or a negative the Estimated Next Due Date becomes today.

As a summary for meter-based PMs you need to ask yourself whether you wish a work order to be generated based on an actual meter reading reaching the point at which a work order will be generated, or whether you accept that a work order can be generated based on an estimated projection using the average units/day of the meter. You can see how important it is to record regular meter readings and if they are not as often as you would like then you may need to set a bigger tolerance, the field ‘Generate WO Ahead By’ . Another factor is the variation in the Average Units/Day over time. If you plotted the number of units consumed per week and there was little variation on this figure over time, then you may allow the projection of the Estimated Next Due Date to generate the work order. If there was a lot of variation over time, then this should tell you that you must use actual meter readings to generate the work order and if you can step up the frequency at which you take the meter readings then you can lower the tolerance value.

Time and Meter Based PM

If there are multiple Meter Based Frequency records, then they all work on an Estimate or Actual basis, they will use the Estimated Next Due Date or Units to Go field respectively. If ‘Generate Work Order Based on Meter Readings (Do Not Estimate)’ is set, then whichever meter reaches a zero or negative Units to Go value will cause the work order to be generated, if not set then the earliest Estimated Next Due Date determines whether a work order will be generated.

All the fields that you see on the Time Based Frequency tab exist in the PM object. The Frequency defaults to zero and if you wish the PM to act only on a meter basis, then you must not add an Estimated Next Due Date on the Time Based Frequency tab as this could cause a work order to be generated even if the Frequency remains as zero.

As soon as an Estimated Next Due Date is added to the Time Based Frequency tab then you should treat this as a time-based PM irrespective of the frequency. A work order will be generated at the Estimated Next Due Date, and it will then be blanked if the Frequency is zero, no further work order will be generated. You can also use this field if you wish to generate a work order on a certain date before the actual meter reading is reached.

If the Frequency field on the Time Based Frequency tab is non-zero then an Estimated Next Due Date will be calculated when the last work order is generated or completed depending on whether it is a Fixed or Floating Schedule. As you should be using Floating Schedules with any meter-based PM, then it is also dependent on the setting for ‘Generate Work Order Based on Meter Readings (Do Not Estimate)’. If this is set, and a work order will be generated when one of the meter’s Units to Go values has reached zero, then a work order may be generated earlier than this if the time-based frequency derived an earlier Estimated Next Due Date or it became earlier when considering the additional Slack Time and any Lead Time. 

When you are using mixed time and meter-based frequencies it makes more sense if the field ‘Generate Work Order Based on Meter Readings (Do Not Estimate)’ is not set, then a work order is generated based on the earliest of any of the Estimated Next Due Date fields whether they are on the Time Based Frequency tab or one of the PM meter records. When it is set this way, Slack Time makes sense.

Time and/or Meter Based PMs

When considering the three fields in the Work Order Generation Information and the use of Time Based and Meter Based Frequencies, then my recommendations would be as follows:

• Fixed Schedule PMs are time-based (USETARGETDATE = 1) and use the Last Start Date field and they have no PM meter records
• Floating Schedule PMs are time-based (USETARGETDATE = 0) and use the Last Completion Date field and they have no PM meter records
• Meter Based PMs are set to be floating (USETARGETDATE = 0) where work order generation is based on actual meter readings (PMACTMETER=1), there is no time based Estimated Next Due Date
• Time and Meter Based PMs are set to be floating (USETARGETDATE = 0) where work order generation is based on estimated meter readings (PMACTMETER=0) or time whichever Estimated Next Due Date is the earliest.

When considering manual or automatic work order generation, Slack Time makes sense for Fixed Schedule PMs and Floating Schedule PMs, it has no effect with Meter Based PMs, and it may be best left as zero for mixed Time and Meter Based PMs. Therefore, I would consider grouping PMs from a work generation basis into three, combining Fixed Schedule PMs and Floating Schedule PMs and keeping the other two methods separated. 

A little word about the Extended Date. This has effect on Fixed Schedule PMs and Floating Schedule PMs by delaying when the next work order will be generated. It is delaying the Time Based Frequency – Estimated Next Due Date. For Meter Based PMs the Extended Date cannot be entered because the Time Based Frequency – Estimated Next Due Date is null. For Time and Meter Based PMs an Extended Date will extend only the Estimated Next Due Date on the Time Based Frequency tab, if the Extended Date is later than any Estimated Next Due Date on a PM meter, then it will have no effect and the Earliest Next Due Date will show the Estimated Next Due Date on the PM meter.

And a final point. An on-demand PM is where there is a zero Frequency and the Estimated Next Due Date remains null. A work order can be generated by deselecting the ‘Use Frequency Criteria?’ field in the Generate Work Orders dialog. If you have a zero Frequency PM with no PM meters and you add an Estimated Next Due Date, then this is now either a Fixed Schedule PM or a Floating Schedule PM, only one work order will be generated because there is no frequency to set the next Estimated Next Due Date after the first work order has been generated. This can be used for a major equipment shutdown where the date of the shutdown will remain unknown until planning is underway. This technique can be used with PM Hierarchies which is the next part of this video, however, if the planning for the shutdown changes don’t forget to change the Estimated Next Due Date on the Time Based Frequency tab as that will be when the work order will be generated, even if the frequency is zero.

PM Hierarchies

There is a PM Hierarchy tab with a Parent field and a table window for the Children. You can either add a PM to a parent so that it becomes a child, or you can use the New Row button to add children to a PM. As a PM exists at the SiteA structural element of a Maximo database that is used for data separation. More level then you can only add to a parent of the same site or add children PMs from the same site.

A PM Hierarchy creates a Work Order Hierarchy when you use the Generate Work Orders action. The work orders are children work orders and not tasks, however a PM in the hierarchy may have a Job Plan with tasks and this creates tasks of the children work orders. The PMs with Job Plans tend to exist at the bottom level of the PM Hierarchy and the PMs higher in the PM hierarchy may have no Job Plan reference, they are being used to group a set of PMs so that they are performed together as a work package. 

A two-level PM Hierarchy that creates a work package of work orders where all PMs have the same frequency can be achieved by using a PM with a Route where the route stops will create child work orders. Therefore, PM hierarchies tend to be used when the frequency in the PM hierarchy is not the same, or when there are more than two levels. Often a PM Hierarchy is matching part of a location or asset hierarchy.

A PM Hierarchy can have more than two levels, for example to model the PM elements performed in a shutdown, but it becomes harder to navigate when you are more than three levels deep as there is no PM hierarchy drill down. In the past I have suggested adding an additional field to group PMs for a shutdown project rather than adding a fourth level to the PM hierarchy. This can be more flexible and avoids breaking the PM hierarchy apart after a shutdown and in preparation for the next shutdown as not all elements of the hierarchy may take place next time. It is also possible for the PM at the bottom level of a PM hierarchy to be based on a Route and this could create an additional level, for each Route Stop. 

PM Hierarchies create work order hierarchies and not a set of single work orders with no parent.

During the work order generation processes Maximo evaluates the PM hierarchy where the field ‘Use this PM to Trigger PM Hierarchy’ is set , it is always set and read-only for the top-level PM, but it may be unset for descendent PMs. If the earliest ‘Earliest Next Due Date’ of a PM in the hierarchy where ‘Use this PM to Trigger PM Hierarchy’ is set, is today or earlier, then Maximo will generate a complete work order hierarchy and not part of it. If a validation fails during work order creation, then generally no work order will be generated. The field ‘Use this PM to Trigger PM Hierarchy’ (USEFREQUENCY) will be found in the Resource Information section at the bottom of the main tab.

There is no PM hierarchy in the Bedford site of the MAXDEMO database but there is one small hierarchy in the Fleet site and for PM SPF01602.

The main tab also has a field marked ‘Has Children?’ which is set when the PM has children. Both this and the field ‘Use this PM to Trigger PM Hierarchy’ could be usefully added to the details area of the Children table window on the PM Hierarchy tab. 

When creating a PM hierarchy for a set of assets or locationsA physical place where assets exist and where work can be performed. More it is easiest to set-up one PM and then use the Duplicate PM action, you cannot duplicate a PM hierarchy. Then, modify the asset, or location and other details. Create the PMs that will be the parents and other ancestors up to the top of the hierarchy before creating the PM hierarchy itself. In this way the status will start out as Draft for all the PMs in the hierarchy and when you come to create the hierarchy, I think you will be less likely to create mistakes. I’ve advised in the past to draw out the hierarchy on a notepad as you create the PM records to make it easier to create the correct hierarchy in one step.

When you change status to ACTIVE the Change Status dialog has a field for ‘Roll New Status to All Child PMs?’. This can be easily applied from the PM at the top of the hierarchy. If you start elsewhere you may run into error messages like ‘BMXAA3149E – Cannot change status to ACTIVE for PM: 1038 when the parent: PM 1037 is DRAFT.’ Maximo wants all the PMs in the hierarchy to be at the same status.

The Delete button at the end of the Children table window removes the PM from the hierarchy it does not delete the PM itself. You can move a PM in the hierarchy to a different parent or remove it from the hierarchy by setting the Parent field null. If the PM is part of a hierarchy the action Delete PM will give an error message ‘BMXAA3147E – Cannot delete a PM that is part of a hierarchy.’

You can only use the Generate Work Orders action from the top-level PM, if you try it elsewhere in the PM hierarchy you will receive the error message ‘BMXAA3190E – PM 1039 is not a top-level PM and cannot generate work orders. You can find the parent of PM 1039 on the PM Hierarchy tab.’. This is irrespective of whether you are using the Use Frequency Criteria, or have not set this as you would do with an on-demand PM. 

Another point that you should be aware of, is that when you generate a PM the asset or location must be at an Operating state or a synonym. This applies to all PMs in the PM hierarchy, and you might find that some but not all PMs in the hierarchy have a work order generated. Maximo may generate the work order corresponding to the PM at the top of the hierarchy but as it works down if it finds a PM with a location or asset that is not at an Operating state or a synonym you will receive an error like ‘BMXAA3186E – The asset or location associated with PM 1038 has a status of NOT READY. Change the status to an Active status to generate work orders.’. Maximo will only consider other paths through the PM hierarchy and will not generate a work order for descendent PMs that failed to generate a work order due to this error message. This should not normally be a problem as PM Hierarchies often mimic the structure of part of a location hierarchy or asset hierarchy and when changing status on a location or asset you can roll the status down the hierarchy.

When the Generate Work Orders action is successful you will receive an information message for each PM in the hierarchy of the form ‘BMXAA3208I – PM 1037 created work order 1524.’ If there are 10 PMs in the PM hierarchy, you will receive 10 messages of this type.

The data from each PM or its associated Job Plan is copied through to its corresponding work order. The sequence field in the Children table window is also copied. The Sequence provides an order for the display of work orders, and it may be used to provide some order for the way work will be performed.

Each PM may have a different frequency, it might be fixed or floating, it may be time or meter based or a combination, however, it is very much easier to understand what is going on if all the PMs in a hierarchy have the same frequency and are working on the same basis with the same Earliest Next Due Date. You might consider setting a frequency only on the top-level PM and allowing this PM to drive when the work orders are generated.

If the frequencies of the PMs in the hierarchy are different or working on a different basis, then it is not easy to work out when the PM hierarchy will generate next as you are looking across several records. If you use the action Generate Forecast, all the PMs in the hierarchy will be forecasted and they will all have a set of identical forecast dates based on the shortest frequency of any PM in the hierarchy where ‘Use this PM to Trigger PM Hierarchy’ is set.

There is another field in the Resource Information section on the main tab of the PM, ‘Child Work Orders and Tasks Will Inherit Status Changes?’. This is normally set and allows the status of all the work orders in a work order hierarchy to be changed from the top-level work order. Depending on the status you set for work orders created from PMs then you may wish this not to be set, for example, if work orders are generated at In Progress state (INPRG) as you may wish work orders to be completed individually rather than risk a change of status being rolled down from above.

Thank you for Watching

I hope you have enjoyed this video on Meter-Based Preventive Maintenance and PM Hierarchies, I hope you found it useful, and thank you for watching. We would like to see you back in our next episode when we will review Preventive Maintenance forecasting. Don’t forget to hit the Subscribe button, and if you enjoyed this video, please give it a thumbs up.

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Until another time, Goodbye.