Siebel Field Service Guide > Preventive Maintenance > About Triggers for Preventive Maintenance >

Time Interval Triggers

Time Interval triggers in a PM plan for an asset determine the dates that the PM Engine schedules PM actions for that asset. The following additional factors can determine these dates:

• Installation date of the asset
• Period of time that you run the PM Engine

Time Interval triggers include the following fields:

• Interval. A time interval in days.
• Valid Start. A number that indicates the first day in the asset life when the corresponding interval applies.
• Valid End. A number that indicates the day in the asset life when the corresponding interval no longer applies.

Example: Using Time Interval Triggers

This topic gives an example of how the PM Engine schedules PM action dates. Table 45 lists the Time Interval triggers that the PM plan includes for an asset that you purchase on June 8.

Time Interval trigger number 1 indicates that for the first day of the asset life, a time interval of 1 day applies. Time Interval trigger number 2 indicates that for the second through the sixth day of the asset life, a time interval of 3 days applies. Time Interval trigger number 3 indicates that for the seventh and subsequent days of the asset life, a time interval of 5 days applies.

If you run the PM Engine from June 8 to June 30, then the PM Engine uses the asset installation date to calculate the PM action dates, because no PM actions currently exist. The PM Engine schedules PM action dates of June 9, 11, 14, 18, 23, 28 as follows:

• For the first day of the asset life (June 9), Time Interval trigger number 1 applies. The engine adds 1 day to the June 8 installation date to obtain the June 9 scheduled date.
• For the second through sixth days of the asset life (June 10 - June 14), Time Interval trigger number 2 applies. The engine adds 3 days to the June 8 installation date to obtain the June 11 scheduled date, and adds 6 days to the June 8 installation date to obtain the June 14 scheduled date.
• For the seventh and subsequent days of the asset life (June 15 - June 30), Time Interval trigger number 3 applies. The engine adds 10 days to the June 8 installation date to obtain the June 18 scheduled date. (The engine adds 10 days, and not 5 days, to obtain a date that is on or after the seventh day of the asset life.)
• The engine adds 15 days to the June 8 installation date to obtain the June 23 scheduled date, and adds 20 days to the June 8 installation date to obtain the June 28 scheduled date.

If you complete the June 28 scheduled action 2 days early on June 26, and if you run the PM Engine for the period of time from June 8 to July 15, then the PM Engine uses this last completion date to calculate the PM action dates. The PM Engine schedules July 1, 6, 11 PM action dates as follows:

• For the seventh and subsequent days of the asset life, Time Interval trigger number 3 applies. The engine adds 5 days to the June 26 completion date to obtain the July 1 scheduled date.
• The engine adds 10 days to the June 26 completion date to obtain the July 6 scheduled date, and adds 15 days to the June 26 completion date to obtain July 11 scheduled date.

If you do not complete the July 11 scheduled action, and if you run the PM Engine for the period of time from June 8 to July 31, then the PM Engine uses this last scheduled date to calculate the PM action dates because the last scheduled action has no completion date. The PM Engine schedules July 16, 21, 26 PM action dates as follows:

• For the seventh and subsequent days of the asset life, Time Interval trigger number 3 applies. The engine adds 5 days to the July 11 scheduled date to obtain the July 16 scheduled date.
• The engine adds 10 days to the July 11 scheduled date to obtain the July 21 scheduled date and adds 15 days to the July 11 scheduled date to obtain the July 26 scheduled date.

Although the interval can be less than 1 day, higher-level processing logic currently prevents triggers from occurring more than once a day.

Restarting Scheduling for Preventive Maintenance Actions

The asset installation date determines the age of the asset. An asset with no installation date has an age of 0 days.

NOTE:  Do not change the installation date of an asset because the existing PM actions become inconsistent with the revised installation date.

Although you cannot change the dates of scheduled PM actions for an asset, you can restart PM action scheduling to go into effect on the current date or a future date. To restart PM action scheduling for an asset, use one of the following methods:

• In the Date Completed field of the latest PM action for the asset, enter the restart date.

  The PM Engine uses the existing Time Interval triggers in the PM plan for the asset and this restart date to schedule PM actions.

• Delete the asset from the PM plan, and create a new PM plan for the asset with new Time Interval triggers.

  The PM Engine uses the revised Time Interval triggers and the asset installation date to schedule PM actions.

• If the PM plan contains only the asset for which you want to restart PM action scheduling, then set an end day corresponding to today for any Time Interval triggers that are in effect on the restart date, delete any Time Interval triggers that are in effect after the restart date, and create new Time Interval triggers to replace the deleted triggers.

  The PM Engine uses the revised Time Interval triggers and the date of the last completed PM action for the asset to schedule PM actions. If no completed PM actions exist, then the engine uses the date of the last scheduled PM action for the asset instead of the date of the last completed action. If no scheduled PM actions exist for the asset, then the PM Engine uses the asset installation date instead of the date of the last scheduled PM action.