Modifying the scheduled dates and the values for the work units in the program

Modifying the scheduled dates and the values for the work units in the maintenance program

This page allows you to modify the details of schedules defined for a specific aircraft maintenance program. Tell me more.

Select the “Edit Schedule Date/Value” link in the “Edit Aircraft Specific Maintenance Program" page.

The “Edit Schedule Date/Value” page appears.

The system displays the following field:

Date Format

The format in which the date and time fields are displayed and to be entered, in this page. This format is displayed from the "User Preferences" business component based on the login user ID. In case the format is not defined, the system displays the date and time format from the "Enterprise Modeling" business component by default.

The system displays the following details in the “Aircraft Details” group box:

Aircraft Reg #	The registration number of the aircraft that is associated to the program.
Aircraft Model #	The aircraft model to which the aircraft belongs.
Sub Fleet #	The sub fleet number to which the aircraft is a part of.

The system displays the following fields in the “Maintenance Program Details” group box:

Maintenance Program #	The maintenance program for which the schedule information must be specified.
Revision #	The revision number of the maintenance program. The system retrieves the latest revision that is in a “Active” or “Fresh” status
Program Desc	The description of the maintenance program.
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Status	The status of the maintenance program, which can be “Fresh”, “Active”, “Inactive” or “Return”.

Enter the following field in the “Work Unit Details” group box:

Work Unit #

Use the drop-down list box to select the work unit for which the dependent work units must be specified. The system loads the drop-down list box with the “Work Unit #” associated to the "Block", "Base", "Non-Block" and "To be decided".

Click the “Get Details” pushbutton.

The system retrieves the following for the “Aircraft Reg #”, “Maintenance Program” and “Revision #” combination.

Work Unit Type	The type of the work unit, which can be “Task”, “Standard Procedure”, “Aircraft Work Package” or “Component work Package”.
Work Unit Desc	The description of the work unit.
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Execution Type	The execution type of the work unit, which can be “Major” or “Minor”.

The system displays the following fields in the “Schedule Details” group box:

Schedule Type	Indicates whether the work unit must be executed only once or repeated at certain intervals. The system displays one of the following: One Time – Indicates that the work unit must be executed only once. Recurring – Indicates that the work unit must be repeated at certain defined intervals.
Update Basis	The mode by which the due dates must be calculated for executing the work units. The system displays one of the following: Schedule – Indicates that the next due dates for carrying out the work units must be calculated based on a fixed interval. Actual Completion – Indicates that the next due dates for carrying out the work units must be calculated based on its previous completion.
Note: For the work units having both dependent and independent schedules, the system leaves the above-mentioned fields blank, if the schedule type and update basis are different for the dependent and independent schedules.
Sch Exec Rule	Indicates the schedule execution rule of the work unit. The system displays one of the following: Earliest – when both date based and usage based schedules are defined for the work unit, the system considers the earliest of the due dates calculated by these schedules. Latest – when both date based and usage based schedules are defined for the work unit, the system considers the latest of the due dates calculated by these schedules.
Initiated/Reset by	The system displays any one of the following options based on the option selected for the Work Unit # in the Program: Self Compliance - Indicates the task would be initiated/ reset on compliance of the same task. This implies that the compliance of this task is not dependant on any other task. Related Task Compliance - Indicates the task, on compliance, would initiate/ reset another task available as part of the same program. The task, which has to be initiated on compliance of a task is based on the “Initiate Schedule” relationship defined for that task in the ‘Maintain Task Relationship’ activity under the ”Maintenance Task” business component.
Dep Sch Indicator	Indicates the type of dependent schedule information defined for the dependent work units of the work package. The system displays one of the following: Dt – If interval value is specified for the dependent work units Usg – If usage-based schedules are specified for the dependent work units Dt / Usg – If both date-based schedules and usage-based schedules are specified for the dependent work units

Enter the following fields in the “Date Based Schedule Details” group box:

Threshold Date

The period from the induction date or the operational date, from which the due dates for the work units must be calculated (Date & Time Format). Data entry in this field is mandatory if you are specifying date based schedules and if the “Schedule Type” field is set to “One Time”

Last Performed Date

The date and time at which the work unit was last performed (Date & Time Format). This date and time must be earlier than or equal to the server date and time.

Next Scheduled Date

The next scheduled date and time of the work unit (Date & Time Format). This field must be left blank, if the ‘Schedule Type’ is set to “Recurring”, and date based schedules are not specified.

NSD is computed and displayed based on the Process Parameter “Next Due computation logic” defined in the “Define Process Entities activity of the “Common Master” business component.

Example:

Consider the following Date Base Schedule:

Parameter Threshold Interval Repeat Interval NSD & Time

FH Null 3 months 30/07/2014

Now say, FH value reached 100 on 20/07/2014 11:00:00 (LPD) and on the same day the task is complied. In this case, NSD = 20/10/2014 11:00:00 AM (i.e. LPD + Repeat Interval)

If the Process Parameter “Next Due computation logic” is set as ‘Exact Date & Time’, NSD is displayed as ‘20/10/2014 11:00:00’.
If the Process Parameter “Next Due computation logic” is set as ‘End of Day’, NSD is displayed as ‘20/10/2014 23:59:59’.

Note: The system updates the last performed date and the next scheduled date of the work unit to all the maintenance programs associated to the work unit, irrespective of their association status and program status.

The system displays the following fields in the “Date Based Schedule Details” group box, on clicking the “Edit Schedules” pushbutton:

Earliest Schedule Date	The earliest scheduled date and time of the work unit.
Latest Schedule Date	The latest scheduled date and time of the work unit.
Alert Date	The date and time at which an alert message will be displayed about an impending due date for work unit execution.
Rem. Days	The number of days and time remaining for executing the work unit. The ‘Remaining Days’ is calculated as the difference of the NSD and the Current date & Time and displayed based on the Process Parameter “Next Due computation logic” defined in the “Define Process Entities activity of the “Common Master” business component. For example, consider that the difference of the NSD and Current Date & Time is 2 days, 2 hrs and 15 min. If the Process Parameter “Next Due computation logic” is set as ‘Exact Date & Time’, Rem. Days = 2D 2H 15M. If the Process Parameter “Next Due computation logic” is set as ‘End of Day’, Rem. Days = 3 (indicating 3 days).

Enter the following fields in the “Date Based Schedule Details” group box:

Terminating Date

The date and time at which the work unit must be terminated (Date Format).

Remarks

Click the icon to display the “View Notes Information” window. You can see the entire history of remarks recorded for the date-based schedule of the task till date.

Change Type

Use the drop-down list box to indicate whether NSD can be modified on modification of Threshold or Interval. The system lists the following values:

Correction - Select this option to indicate that the NSD specified can be overwritten on modifying the Threshold or Interval.
Re-baseline - Select this option to indicate that the NSD specified cannot be overwritten on modifying the Threshold or Interval.

Data selection in this field is mandatory, if ‘Last Performed Date’ or ‘Next Scheduled Date’ is modified. You cannot modify the Change Type, if ‘Repeat Interval’ or ‘Threshold’ is modified.

By default, the system leaves the field blank.

The system displays the following fields:

Next Due Calc. On

The computation basis of Next Schedule Date (NSD). The system displays various values depending on the basis on which NSD is computed.

If the NSD computation basis is ‘Reference Basis’, values displayed are:

Induction Date
Operational Date

If the NSD computation basis is ‘Update Basis’, values displayed are:

Time Window
Schedule
Actual Completion

If the NSD computation basis is ‘Schedule Reset Basis’, following values are displayed:

STE : Actual Completion
STE : Last Schedule

If the NSD computation is based on the Change Type selection, the system displays the following values:

Manual : Correction
Manual : Re-baseline

If the compliance of parent task triggers Related Task Compliance, the following value is displayed:

RTC

If the user modifies interval / threshold and by removing NSV, the following value is displayed:

Initial Interval

Calc. Ref. Date

The reference date based on which NSD is computed.

Last Schedule Date

The actual schedule date of task on last compliance.

Note: On releasing the engineering document, the system updates the NSD / NSV and the NSD / NSV computation basis controls ‘Next Due Calc. On’, ‘Calc. Ref. Date’ and ‘Last Schedule Date / Value’ in various scenarios, as explained in the table.

The system displays the following fields in the “Usage Based Schedule Details” multiline:

Parameter	The parameter based on which the work unit is performed.
Note: If the work unit has dependent and independent schedules, all the parameters that are available for the dependent and independent schedules are listed separately.
Unit Of Measurement	The unit of measurement of the parameter.

Enter the following fields in the “Usage Based Schedule Details” multiline:

Threshold Value

The parameter value at which the first execution of the work unit is due (Decimal).

Last Performed Value

The last parameter value at which the work unit must be performed (Decimal).

Next Schedule Value

The parameter value at which the work unit is next due for execution (Alphanumeric, 40).

This field is mandatory, if you have not specified the Last Performed Date for a parameter of a task with the Schedule Type as “Recurring”, and the Initiated/Reset by as “Self Compliance.

Note: By default, the system displays the threshold value, last performed value and the next schedule value. The system calculates these values by applying the schedule execution rule specified for the work unit in the “Sch Exec Rule” field.

The system displays the following fields in the “Usage Based Schedule Details” multiline, on clicking the “Edit Schedules” pushbutton:

Earliest Schedule Value	The earliest parameter value at which the work unit must be executed.
Latest Schedule Value	The latest parameter value at which the work unit must be executed.
Alert Value	The parameter value at which an alert message is displayed for an impending execution due for the work unit.
Rem. Value	The difference between the current parameter value and the next due parameter value.
Next Due Calc. On	The computation basis of NSV.
Calc. Ref. Value	The reference value based on which NSV is computed.
Last Schedule Value	The actual schedule value of task on last compliance.

Enter the following fields in the “Usage Based Schedule Details” multiline:

Change Type

Use the drop-down list box to indicate whether NSV can be modified on modification of Threshold or Interval. The system lists the following values:

Correction - Select this option to indicate that the NSV specified can be overwritten on modifying the Threshold or Interval.
Re-baseline - Select this option to indicate that the NSV specified cannot be overwritten on modifying the Threshold or Interval.

Data selection in this field is mandatory, if ‘Last Performed Value’ or ‘Next Scheduled Value’ is modified. You cannot modify the Change Type, if ‘Repeat Interval’ or ‘Threshold’ is modified.

By default, the system leaves the field blank.

Terminating Value

The parameter value, reaching which the work on the work unit must be terminated (Decimal). Ensure that you enter a positive value in this field.

The system displays the following field on clicking the “Edit Schedules” pushbutton.

Parameter Description

The description of the parameter.

Remarks

Any remarks pertaining to the task and parameter can be entered here. (Alphanumeric, 2000).

Click the Remarks icon to display the “View Notes Information” window. You can see the entire history of remarks recorded for the parameter till date.

Click the “Edit Schedules” pushbutton.

Note: You cannot modify Last Performed Date, Next Schedule Date, Threshold (if task is not complied at least once), Last Schedule Value or Next Schedule Value, if there exists an open escalation for a task.

The system performs the following:

Saves the schedule details against the maintenance program.
For the work unit having dependent/independent schedule, the system calculates the schedule dates, based on the intervals specified in the dependent/independent schedule, by applying the schedule execution rule specified in the “Sch Exec Rule” field. The following table explains the values calculated by the system under different circumstances:

When…	System calculates and updates…
Last performed date alone is entered in the “Date Based Schedule Details” group box	Next schedule date, earliest schedule date, latest schedule date, alert date and terminating date for the work unit and its dependent work units (if existing)
Next schedule date alone is entered in the “Date Based Schedule Details” group box	Earliest schedule date, latest schedule date, alert date and terminating date for the work unit
Last performed date and the next schedule date are entered in the “Date Based Schedule Details” group box	Earliest schedule date, latest schedule date, alert date and terminating date for the work unit and its dependent work units (if existing)
Last performed value alone is entered in the “Usage Based Schedule Details” multiline	Next schedule value, earliest schedule value, latest schedule value, alert value and terminating value for the work unit and its dependent work units (if existing)
Next schedule value alone is entered in the “Usage Based Schedule Details” multiline	Earliest schedule value, latest schedule value, alert value and terminating value for the work unit
Last performed value and next schedule value are entered in the “Usage Based Schedule Details” multiline	Earliest schedule value, latest schedule value, alert value and terminating value for the work unit and its dependent work units (if existing)

Note: If the time unit for date-based calculation is set as “Years” or “Months”, the system converts it into “Days” for calculation.

If the time unit is “Month End”, the system considers the last performed date and time as the last day of that month. For example, if the actual last performed date is 6th April 2004 11:34:50 and if the time unit is set as “Month End”, the system considers 30th April 2004 11:34:50 as the last performed date for all calculations.

If the Eng. doc reference # exists for the task, the system allows you to modify the Date based / usage based schedule details (such as threshold / interval of the Eng. doc task), only if the process parameter “Allow modification of Eng. Doc. task in Maintenance Program” is set as “Allowed” in the “Define Process Entities” activity of the “Common Master” business component.

Note: You can modify the Next schedule Date / Value and Last Performed Date / Value, irrespective of the option setting in the “Common Master” business component.

Computation of Next Schedule Date (NSD) / Next Schedule Value (NSV)

If you specify “Initiated/Reset by” for a task in an aircraft maintenance program as "Related Task Compliance”, then system does not automatically compute the NSD/ NSV. However, if you have specified the NSD/ NSV, the system retains these values.
NSD / NSV is computed and updated as shown in the table below:

NSD Computation:

Last Performed Date	Schedule Type	Repeat Interval	Threshold Interval	Next Schedule Date (NSD)
Available	One Time	-	-	NSD update does not happen
Available	Recurring	Available	-	Reference Date + Repeat Interval
Available	Recurring	Not Available	-	NSD update does not happen
Not Available	Recurring	Available	Not Available	Reference Date + Repeat Interval
Not Available	-	-	Available	Reference Date + Threshold Interval
Not Available	-	Not Available	Not Available	NSD update does not happen
Not Available	One Time	-	Available	Threshold Date
Not Available	One Time	-	Not Available	Threshold Date

NSV Computation:

Last Performed Date	Schedule Type	Repeat Interval	Threshold Interval	Next Schedule Date (NSD)
Available	One Time	-	-	NSV update does not happen
Available	Recurring	Not Available	-	NSV update does not happen
Available	Recurring	Available	-	Last Performed Value + Floating Interval
Not Available	One Time	-	Not Available	NSV update does not happen
Not Available	One Time	-	Available	Threshold Interval
Not Available	-	Not Available	Not Available	NSV update does not happen
Not Available	-	Available	Not Available	‘0’ + Floating Interval
Not Available	-	-	Available	Threshold Interval
Not Available	Recurring	-	Not Available	Repeat Interval

The system updates the ‘Next Due Calc. On’, ‘Calc. Ref. Date’ and ‘Last Schedule Date / Value’ based on the ‘Change Type’ selected and the value entered by the user, as shown as below:

‘Change Type’ selected	Value entered by user	Compliance Status	Next Due Calc. On	Calc. Ref. Value / Date	Last Schedule Date / Value
Correction	NSD / NSV	Pre-Compliance	Manual : Correction	Not Applicable	Not Applicable
Correction	LPD / LPV	Pre-Compliance	Manual : Correction	Date and Time / Value entered by user	Not Applicable
Correction	NSD / NSV, LPD / LPV	Pre-Compliance	Manual : Correction	Date and Time / Value entered by user	Not Applicable
Re-baseline	NSD / NSV	Pre-Compliance	Manual : Re-baseline	Date and Time / Value entered by user	Not Applicable
Re-baseline	LPD / LPV	Pre-Compliance	Manual : Re-baseline	Date and Time / Value entered by user	Not Applicable
Re-baseline	NSD / NSV, LPD / LPV	Pre-Compliance	Manual : Re-baseline	Date and Time / Value entered by user	Not Applicable
Correction	NSD / NSV (Modified)	Post Compliance	Manual : Correction	Date and Time / Value entered by user	Last Due Value or Date and Time
Correction	LSD / LSV (Modified)	Post Compliance	Manual : Correction	Value entered by user	Last Due Value or Date and Time
Correction	LSD / LSV (Modified)	Post Compliance	Manual : Correction	Date and Time / Value entered by user	Last Due Value or Date and Time
Re-baseline	NSD / NSV (Modified)	Post Compliance	Manual : Re-baseline	Date and Time / Value entered by user	Last Due Value or Date and Time
Re-baseline	LSD / LSV (Modified)	Post Compliance	Manual : Re-baseline	Value entered by user	Last Due Value or Date and Time
Re-baseline	LSD / LSV, NSD / NSV (Modified)	Post Compliance	Manual : Re-baseline	Date and Time / Value entered by user	Last Due Value or Date and Time

Modifying the scheduled dates and the values for the work units in the maintenance program – An overview

This page allows you to modify the details of schedules defined for a specific aircraft maintenance program. You can retrieve a work unit that must be performed as a part of the program and enter the date and time at which the work unit was last performed. You can also modify the threshold date and time and the next scheduled date and time of the work unit. Based on the schedules that are defined for the work unit, the system re-calculates the next scheduled due dates of the work unit in the maintenance program.