Calculation for Units to Go in Preventive Maintenance (CM)

Needless to say, the calculation of units to go in ACM is a bit trickier than how it’s calculated in base Maximo. People who have worked on it can understand where I am coming from.


Units to Go is calculated based on the PLUSALFEVENT (Maintenance Event) record which is created when the PM is made ACTIVE. These are the records displayed in the Maintenance Plan tab in the Asset (CM) application.

It is these PLUSALFEVENT records that are utilized by the BDI process to decide when Work Orders should be created from the PMs and also to decide whether the PM is overdue, past its warning point etc.

The ‘Left’ value on the Maintenance Plan tab is essentially the units to go for the associated PM in Assets (CM).

The calculation for units to go is:

Units to Go = Due Count – Current Count

Where Due Count = Active Count + PM Meter Frequency

The Active Count is the meter count calculated at the Active Date of maintenance event (PLUSALFEVENT.ACTIVEDATE).

Every time a work order for a maintenance event is completed, a new maintenance event (PLUSALFEVENT) entry is created with an Active Date same as that of the work order completion date. The same date is stamped as inactive date on the old maintenance event record.

So every time the active date from the most recent maintenance event record is used to calculate the Due Count for the PM.

The Current Count is the meter count at the current system date and time.

Alert and Warning Intervals in PM (CM)

Alert and warning interval in Preventive Maintenance (CM) have always been confusing. Let me explain you what they are and how to set them.

Alert interval is the point at which a work order is generated. This interval is checked by BDI to generate work order.

Warning interval is the point at which a warning is issued to inform you that a preventive maintenance (PM) record is almost overdue.This interval is checked by BDI to generate warning.

The Assets (CM) application color-codes warnings and overdue PMs.

If the alert interval is null, BDI would create the work order at the moment the PM is generated. So it should never be null.

When setting the alert and warning interval, the Alert and Warning Interval State plays an important role. Here’s how –

Consider a PM with time based frequency as 30 days. Work order for this PM should be created on the 24th days and the warning should be shown from the 27th day. Let’s see how the alert and warning interval should be set to achieve this based on different interval state.

Alert Warning 01

Alert Warning 02

Alert Warning 03

Alert Warning 05

Alert Warning 06