Entering usage-based schedule for a work unit

This page allows you to specify the usage-based schedule details for the work units that are associated with the component maintenance program. Tell me more.

Select the “Edit Usage-based Schedule” link at the bottom of the “Edit Component Maintenance Program Information” page.

The “Edit Usage-based Schedule Information” page appears.

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

Part #	The number identifying the part for which the usage-based schedule must be defined.
Part Description	The textual description of the part.
Component #	The number identifying the component for which the usage-based schedule details must be updated.
Serial #	The serial number of the component.
Maintenance Process	Indicates the maintenance process associated with the part, which could be “Hard-Time”, “On-Condition” or “Condition Monitoring”.
CMP Status	The status of the maintenance program, which could be “Fresh” or “Authorized”.
Revision #	The revision number of the component maintenance program.

Enter the following in the “Maintenance Activity Details” group box:

Work unit #

Use the drop-down list box to select the work unit for which the date-based schedule must be specified. The system lists all the work units except those with Program Item Type-Perpetual and As Required from the part maintenance program; prefixes work units with “TSK”, “SP” or “WP” based on the type of the work unit.

Click the “Get Details” pushbutton to retrieve the usage-based schedule details that are already defined for the work unit.

The system displays the following after you click the “Get Details” pushbutton:

Work Unit Description	The textual description of the task, standard procedure or work package.
Maintenance Type	The type of the maintenance activity to be carried out.
Work Center #	The work center where the work unit is performed.
Work Center Description	The textual description of the work center.

Note: For work units of type "Work Package", the system also retrieves parameter codes defined in the work package that are mapped to the part number as defined in the "Aircraft" business component.

Enter the following in the “Usage-based Schedule Details” multiline:

Parameter	A number that identifies the consumption parameter in the aircraft or its component (Alphanumeric, 40). Mandatory. This parameter must be of the “Consumption” type defined in the “Create Parameters” activity of the “Aircraft” business component and must be in the “Active” status. The periodicity of the task will be decided based on the values of the consumption parameters.
	Help facility available.

The system displays the following field after you click the “Edit Usage-based Schedule” pushbutton:

UOM

The unit of measurement of the parameter.

Enter the following:

Schedule Type

Use the drop-down list box to specify whether the work unit has to be performed on a “One-Time” or “Recurring” basis.

This field should be set as “One-Time”, if the “Maintenance Type” of the work unit is “Retire”.

The schedule type is mandatory, if Remarks is provided regarding the maintenance program planned for the part.

Last Performed Value

The number entered in this field must be positive. The value entered here must be less than the current value of the parameter.

Note: In the event of modifying an already associated parameter and schedule type, the system displays an error message. Also, to delete an existing parameter and schedule type, check the box in the “Select” column of the multiline and click the Delete icon.

The system displays the following

Current Value

The current value of the parameter.

Enter the following:

Next Schedule Value	The number entered in this field must be positive. The value entered here must be greater than the last performed value and lesser than the threshold value. Data entry in this field is mandatory if the Schedule Type” is “One-Time” and the “Last Performed Value” and “Threshold” fields are left bank. You must not enter Next Schedule Value, if the component is not attached in an Aircraft and if ‘Reset on Attachment?’ for the task is selected as “Every Attachment”.
Threshold	The maximum number of days or hours within which, the work unit for the consumption parameter, is to be carried out (Decimal). Data entry in this field is mandatory if the “Schedule Type” is set as “One-Time”. Ensure that the number entered in this field is positive.
Note: If the parameter is set as a “Life Parameter” in the “Edit Consumption and Range Parameters” page of the “Aircraft” business component, the next schedule value and the tolerance value must be less than the “Ultimate Life Value” set for the parameter in the “Edit Consumption and Range Parameters” page.
Interval	The maximum number of days or hours within which the work unit for the consumption parameter is to be repeated (Decimal). Ensure that the number entered in this field is positive.
Alert Value	The value or date after which an alert needs to be given for the impending work unit execution (Decimal). Ensure that the number entered in this field is positive.
Positive Tolerance	The upper limit of the time interval within which the work unit is to be performed (Decimal). Ensure that the number entered in this field is positive.
Negative Tolerance	The lower limit of the time interval within which the work unit is to be performed (Decimal). Ensure that the number entered in this field is positive.

The system displays the following field:

Next Due Calc. On

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

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

Time Window
Schedule
Actual Completion

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

STE : Actual Completion
STE : Last Schedule

If the NSV 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:

If the user modifies interval / threshold and manually enters NSV, the following value is displayed:

Initial Interval

Calc. Ref. Value

The reference value based on which NSV is computed.

Last Schedule Value

The actual schedule value of task on last compliance.

Note: 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.

Enter the following:

Change Type

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

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

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

By default, the system leaves the field blank.

Terminating value

The value after which the maintenance activity cannot be performed on the component (Decimal). The "Last Performed Value", "Next Scheduled Value" and "Threshold Value" should be less than the "Terminating Value".

Note: The terminating value entered should be less than the “Ultimate Value” defined for the parameter of the component or part # in the “Aircraft” business component.

Ensure that at least one schedule detail is entered in the multiline.

The system displays the parameter values in the multiline based on the option “Decimal Format” or “HHMM Format” selected for the parameter in “Time Display Option” drop-down list box in the “Aircraft” business component while parameter creation. For e.g. If the Time Display Option is selected as “HHMM Format” and the value stored is 2.50 in the data base, the system displays 2.30 in the multiline.

Remarks

Any comments or supplementary information on the maintenance schedule planned for the component (Alphanumeric 2000).

Note: Select the row and click the Remarks icon to display the “View Notes Information” window. You can see the entire history of notes recorded for the parameter till date.

Click the “Edit Usage-based Schedule” pushbutton to update the usage-based schedule information.

Note: You can update the schedule details for a task only if the maintenance operator associated with the task is also mapped to the login user, if the process parameter "Allow addition/modification of tasks from other Maint. Operator codes in Part Program?" under the 'Tech. Records Process Ctrl' entity type and 'Part Prog' entity is set as '0' for No in the Define Process Entities activity of Common Master.

The system performs the following on updating the usage-based schedule details.

NSV Calculation:

If ‘Reset on Attachment?’ is selected as “Not Required” / “First Attachment”, Next Schedule Value is calculated as follows:
1. For the one-time schedule, if the last performed value is specified and the next schedule value is left blank, the system updates the threshold value as the next schedule value.

Note: If the “Threshold value” entered is less than the current value, the system will not update the threshold value as the next schedule value.

Note: If one-time schedules are included in a part program through an EO during automatic CMP generation, and if “Effective From Date” is specified for the EO, the system calculates the next schedule value by considering the “Effective From Date”. If “Effective From Date” is not defined, the system considers the “EO Release Date” for the next schedule value calculation.

1. For the recurring schedule, if the next schedule value is not given, the system updates the next schedule value as follows:

If Last Performed value is available:

Next schedule value = Interval + Last Performed Value (if available)

else

Next schedule value = Threshold Value (only when Threshold Value is greater then Current parameter value)

If Last Performed Value is not available and Threshold Value is lesser than the Current parameter value, then system won’t compute Next Schedule Value.

If the calculated next schedule value is lesser than the threshold value, the system updates the threshold value as the next schedule value.

Example:

If the 'Compliance Updation Basis' is set as “Time Window” in the “Set Options” activity, and if the work unit is executed within the tolerance limits then the next due will be assumed to be the Next Schedule Value (NSV). If the work unit is executed beyond the tolerance limits, then NSV will be the sum of the Parameter value at which the work unit is executed and the repeat fixed interval value / repeat floating interval value.

Consider that the work unit is next due on 6000FH, repeat interval is 600FH and tolerance is +/- 10FH, If the work unit is executed at any parameter value between 5990 FH to 6010 FH (both values included), then

NSV = 6600 FH. (6000 FH + 600 FH)

If the work unit is executed at any parameter value beyond the limits (5990 FH to 6010 FH), i.e. if the work unit is executed on say, 5989 FH or 6015 FH, then

NSV will be 6589 FH and 6615 FH respectively.

Note: If multiple parameters associated to the work unit, NSV is calculated for each of the parameter based on Time Window.

If ‘Reset on Attachment?’ is selected as “Every Attachment”, NSV is calculated as follows:

if the component is attached to Aircraft and Last Performed Value is blank,

NSV = Threshold Value + Parameter Value on Last Installation Date

If Last Performed Value exists for a task and the component is attached to Aircraft,

NSV = Interval + Parameter value of the component on Last Installation Date.

If the component is not attached to Aircraft, NSV is updated as ‘blank’.

If threshold value / interval is modified and NSV is blank,

NSV = Modified Threshold Value / Interval + Parameter Value of the component on Last Installation Date

If the parameter value of a component or any of its lower level children is changed due to one of back-dated journey logs, journey log amendments, back-dated component removals, amendment of component replacement record and reversal of component replacement records, the system updates the next schedule value and compliance value for one-time schedules. For recurring schedules, the system recalculates the next schedule value by adding the interval to the revised last performed value.
Update of computation basis controls - Section A
Update of computation basis controls - Section B
If the Eng. doc reference # exists for the task, the system allows you to modify the following schedule details of the Eng. Doc. task in the Maintenance Program, 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.

Schedule Type
Update Basis
Usage Based Schedule details

Note: You can modify the Next Schedule Value and Last Performed Value irrespective of the option setting.

Entering usage-based schedule for a work unit – An overview

This page allows you to specify the usage-based schedule details for the work units that are associated with the component maintenance program. These schedules are dependent on the usage of the component and are based on the consumption parameters of the component. The schedule for the next performance of a work unit will be specified in terms of the value of the consumption parameter.

Usage-based schedules can be one-time or recurring. One-time means, that the schedule will be performed only once, when the corresponding parameter reaches the specified value. In the case of recurring, the maintenance activity will be performed every time the parameter crosses the interval mentioned.

Alert value or date specifies the value or date after which the corresponding work unit is considered in the component maintenance forecast. You can also specify the positive and negative tolerance, which indicates the limits of the execution date within which the work units is to be performed.

The system updates the date-based schedule details and stores the name of the currently logged in user and the current server date.

Note: The system will not allow you to define usage-based schedules for a work unit if the "Shelf Life Expiry" field for that work unit is set to "Yes" in the "Edit Component Maintenance Information" page.

What you can do in this page

Indicate work unit schedule type for parameter

Usage-based schedules can be of one-time or recurring type. In the case of one-time schedule, the work unit will be performed only once when the corresponding parameter reaches the specified value. In the case of recurring schedule, the work unit will be performed every time the parameter crosses the interval mentioned.

Set the “Schedule Type” field as “One-Time” to indicate that the work unit is to be performed only once.
Set the “Schedule Type” field as “Recurring” to indicate that the work unit is to be performed in repeated intervals.