Preventive Maintenance – Time Based

Maximo Bite Size
Maximo Bite Size
Preventive Maintenance – Time Based

Good morning and welcome to Maximo Bite Size, a podcast on the functionality of Maximo Manage. Today is the eighth episode in the series on Maintenance Planning and we will be discussing Time-Based Preventive Maintenance.

The Preventive Maintenance application supports frequency-based maintenance, time, meter or time and meter. It also supports non-frequency-based maintenance and I’ll discuss this after talking about time-based maintenance. We shorten the term Preventive Maintenance to PM and often the work type is PM, but the application can be used for anything which is frequency based, inspections for example.

When a PM record is created you would enter a location or an asset, they are mutually exclusive. Alternatively, you can reference a Route with or without an Asset or Location reference. One of the three fields will normally be required but if you leave all three empty and try to save the record you will find that either one of these fields is needed or a GL Account is needed.

For time-based PMs there is a frequency and a frequency unit, Days, Weeks, Months or Years. The other decision you need to make is whether the frequency is fixed or floating. The checkbox titled “Use Last Work Order’s Start Date to Calculate Next Due Date?” defaults to checked and this is considered a fixed interval. The Estimated Next Due Date is entered to indicate when the PM will next be performed, say this is 1-Jan-23 and the frequency is every 3 months, then work orders are generated at fixed intervals 1-Apr-23, 1-Jul-23, 1-Oct-23, etc, irrespective of when the work order was completed. It is generating the next work order based on the target start date of the last work order. If the checkbox titled “Use Last Work Order’s Start Date to Calculate Next Due Date?” is unchecked, then it is a floating schedule, the next work order will be generated based on the actual finish date of the previous work order generated from this PM.

If a PM cannot be completed by the Estimated Next Due Date you can provide an Extended Date, and this changes the Earliest Next Due Date that you see on the main PM tab. If you are working fixed intervals you can determine with the Adjust Next Due Date whether after the next work order generation from the PM whether the recalculation of the Earliest Next Due Date uses the set frequency from the Extended Date, or the old Estimated Next Due Date. For example, the Estimated Next Due Date is 1-Jul-23 but there is a shutdown in progress at that time and you know resources will be short, you provide an Extended Date of 17-Jul-23. Using the Adjust Next Due Date will mean that the next 3 monthly PM work order will have a target start date of 17-Oct-23, if this field is unchecked it will be 1-Oct-23 as originally planned.

The Target Start Time is used to set the time of day for the work order target start date, if it isn’t set it will be 00:00. Normally this is set to the start time of the shift which would normally perform the PM work orders.

When a work order is generated, we should be indicating the job type to be performed, this is a Job Plan. A PM can either reference one job plan in which case this is applied to each work order generated from the PM, or you can define a Job Plan Sequence. For example, our 3 monthly PM may have slightly different jobs performed at 6 monthly intervals and at 12 monthly intervals. The three job plans which define the tasks to be performed can be set up in a sequence of 1, 2, and 4. Every 2nd time a work order is generated (every 6 months) a different job plan is performed, every 4th time a work order is generated then the annual job plan is applied. For the 1st, 3rd, 5th and odd numbered work orders the 3-monthly job plan is applied to the generated work order.

The job plan to apply to the generated work order the next time around is determined by the PM counter field. This is a read-only field that is modified by the action Set PM Counter. For example, if the next work order to be generated will be the annual PM, then the PM counter would be set to 3. The View Sequence action allows you to visualise the order of job plans to be applied over time and is useful after using the Set PM Counter action.

Seasonal based PMs are defined on the Seasonal Dates tab. You can set the active days of the week for the generated work order’s target start date, for example we only want the target start to be a Monday through Friday and the Active Time field is set to be the Target Start Date’s time, e.g., 08:00. If the next due date is a Saturday or Sunday, you can determine whether to Schedule Early on Frequency Conflict which if checked will make the Target Start Date of the generated work the Friday, otherwise the default (when unchecked) is to generate the work order on the next available active day of the week, i.e. Monday.

The fields in the section called Work Order Information are values that will be copied to the work order when it is generated from the PM. The fields to set are the Work Type, Work Order Status and Priority. The two Constraint Offset fields are a numeric number of hours either side of the target start date which will define the Start and Finish Constraint Dates, a time window in which the work order should be scheduled. For example, 14 days (an offset of 336 hours) for both the Start and Finish Constraint Offsets will create a 4-week period around the target start date when the work order should be scheduled.

The Responsibility section has seven fields that you will also find in the Responsibility section of a work order in the Work Order Tracking application and in the Job Plans application. There are various rules for determining whether to accept a default from the Job Plan or the PM and in the Links section at the bottom of the transcript I will provide a link to an article I have written on this subject. Incidentally, the Responsibility section on the Work Order Tracking application has one extra field that is not on the Preventive Maintenance or Job Plans applications, it is the Vendor.

There are a few other fields that may be set depending on the situation:

On the Seasonal Dates tab, apart from the active days of the week you can set one or more periods which are the active periods which if the next due date falls within the active period, then a work order will be generated. If it falls outside of the active periods, then the work order will next be generated for the first day of the next active period.

The Preventive Maintenance application has a simple set of statuses for a PM, the default is DRAFT, and it is then made ACTIVE, at some future point it may become INACTIVE. At no status does the PM record become read-only.

You can only generate work orders from PMs that are at ACTIVE state. To generate work orders the location or asset referenced on the PM must be at OPERATING status or one of its synonyms.

In the action Generate Work Orders the field called ‘Generate WOs Due Today Plus This Number of Days’ is known as the slack time. This is used when work orders are created in batch, i.e. you set the slack time to seven if you generate work orders for the week ahead, or to thirty when generating work orders for the next month. The Lead Time set on each PM is added to the Slack Time to determine whether a work order is generated.

Normally the Use Frequency Criteria field is set, i.e. the work orders will be generated based on the time or meter-based frequencies. However, for the current PM you may wish a work order to be generated immediately, for example, a system must be shut down for an unexpected reason, and while the assets are shutdown some PM work can be performed irrespective of the frequencies. You can then clear the Use Frequency Criteria and generate a work order; this can also operate across a selected set of PMs from the List tab of the application.

Another reason for ignoring the frequency criteria is for PMs where you set the frequency to zero. If there is a zero frequency, no work order will be generated during the normal batch processing of PMs. These zero frequency PMs might be used for generating work orders on-demand, for example the work orders performed when a system is shutdown, or when an infrequent event occurs. We’ll come back to this again when we talk about Meter Based PMs and PM Hierarchies, because this technique is sometimes used when you group PMs together.

PM Work Generation can be set to operate in the background and to email you when all work orders have been generated. In the Organizations application and PM Options action, the PM Options section sets the defaults for the Generate Work Orders action. There are two other fields for determining whether the work order priority comes from the job plan or the PM, and for setting the work order status of a CM work type work order that will trigger the work order alert process.

Automatic Work Order generation can also be set using a Cron Task called PMWoGenCronTask. When this is used the parameters for each site are determined from the section called Stand-alone PM Work Order Generation Process Settings. The ‘Automatic PM Wo Generation’ field needs to be set and you can provide an optional ‘WO Generation Where Clause’ to restrict the set of PMs for which automatic generation on the site will be made.

I hope you enjoyed this podcast episode and I look forward to seeing you in the next episode when we will continue our discussion on Preventive Maintenance with Meter-Based PMs and PM Hierarchies.

The music is called Drag Race from the group called TrackTribe, please check them out on, all one word.

Until another time, goodbye.


Responsibilities on Job Plans, PMs and Work Orders – Responsibilities on Job Plans, PMs and Work Orders

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