Scenario-wise illustration of NSD and NSV
Scenario 1: “Initiated/Reset by” = “Self-Compliance”
The Next Scheduled Date (NSD) computation for date-based schedule tasks
|
Last Performed Date |
Repeat Interval (Fixed or Floating) |
Threshold Interval |
Schedule Type |
‘Reset on Attachment?’ (Applicable only for CMP) |
Next Scheduled Date (NSD) |
|
Available |
- |
- |
One Time |
Not Required / First Attachment / Every Attachment |
NSD update does not happen |
|
Available |
Available |
- |
Recurring |
Not Required |
Reference Date + Repeat Interval |
|
First Attachment / Every Attachment |
Last Installation Date + Repeat Interval |
||||
|
Available |
Not Available |
- |
Recurring |
- |
NSD update does not happen |
|
Not Available |
- |
Not Available |
Recurring |
- |
NSD update does not happen |
|
Not Available |
- |
Available |
Recurring |
Not Required |
Threshold Interval + Reference Date |
|
First Attachment / Every Attachment |
Threshold Interval + Last Installation Date |
||||
|
Not Available |
Not Available |
Not Available |
Recurring |
- |
NSD update does not happen |
|
Not Available |
- |
Available |
One Time |
Not Required |
Threshold Date |
|
First Attachment / Every Attachment |
Threshold + Last Installation Date |
||||
|
Not Available |
- |
Not Available |
One Time |
- |
Threshold Date |
Note: If the component is not attached to the aircraft, NSD is not updated in the Component Maintenance Program.
The Next Scheduled Value (NSV) computation for usage-based schedule tasks
|
Last Performed Value |
Repeat Interval (Fixed or Floating) |
Threshold Interval |
Schedule Type |
‘Reset on Attachment?’ (Applicable only for CMP) |
Next Scheduled Value (NSV) |
|
Available |
- |
- |
One Time |
- |
NSV update does not happen |
|
Available |
Not Available |
- |
Recurring |
|
NSV update does not happen |
|
Available |
Available |
- |
Recurring |
Not Required / First Attachment |
Floating Interval + Last Performed Value |
|
Every Attachment |
Floating Interval + Parameter value on Installation Date of the Component |
||||
|
Not Available |
- |
Not Available |
One Time |
- |
NSV update does not happen |
|
Not Available |
- |
Available |
One Time |
Not Required / First Attachment |
Threshold Value |
|
|
|
|
|
Every Attachment |
Floating Interval + Parameter value on Installation Date of the Component |
|
Not Available |
Not Available |
Not Available |
- |
- |
NSV update does not happen |
|
Not Available |
Available |
Not Available |
- |
Not Required / First Attachment |
‘0’ + Floating Interval |
|
Every Attachment |
Floating Interval + Parameter value on Installation Date of the Component |
||||
|
Not Available |
Not Available |
Available |
- |
Not Required / First Attachment |
Threshold Value |
|
Every Attachment |
Threshold Value + Parameter value on Installation Date of the Component |
Note: If the component is not attached to the aircraft, NSV is not updated in the Component Maintenance Program.
If “Initiated/Reset by” is set to “Related Task”, the system computes the Next Scheduled Date (NSD) as shown in the table below.
Scenario 2: “Initiated/Reset by” = “Related Task”
Note that when the “Initiated/Reset by” is set to “Related Task” for a task, the system computes the NSD and NSV on the basis of the Last Complied Date of the related task. However, if a task has multiple related tasks sharing “Initiate Schedule” relationship, the Last Complied Date of the task that is the latest forms the base for arriving at the NSD or NSV of the task. This is elucidated in the following tables.
Computation of NSD: Main Task: T1, Related Task: T2, Relationship: “Initiate Schedule”
Let us assume that from among the several tasks that share “Initiate Schedule” relationship with T1, T2 has the latest compliance date and hence T2 is used to initiate T1.
|
Repeat Interval (Fixed or Floating) |
Last Complied Date |
Next Scheduled Date (NSD) |
|
Available |
Available |
Last Performed Date of T2 + Repeat Interval |
|
Not Available |
Not Applicable |
Blank |
Computation of NSV: Main Task: T1, Related Task: T2, Relationship: “Initiate Schedule"
|
T1-Parameter |
Last Performed Value |
Repeat Interval (Fixed or Floating) |
Threshold Interval |
Next Scheduled Value (NSV) |
|
FH |
Available |
Available |
Available |
Parameter Value as on Last Complied Date of T2 + Repeat Interval |
|
FC |
Not Available |
Not Applicable |
Available |
Blank |
Scenario 3: Task with a Short term escalation request
Computation of NSD: “Schedule Reset Basis” = “Deferred Value”
|
Last Performed Date |
Due Date |
Repeat Interval (Fixed or Floating) |
Next Scheduled Date (NSD) |
|
Available |
Not Applicable |
Available |
Last Performed Date + Repeat Interval |
|
Not Available |
Not Applicable |
Available |
Blank |
Computation of NSV: “Schedule Reset Basis” = “Deferred Value”
|
T1-Parameter |
Due Date |
Last Complied Value |
Repeat Interval (Fixed or Floating) |
Next Scheduled Value (NSV) |
|
FH |
Not Applicable |
Available |
Available |
Parameter Value as on Last Complied Date of T2 + Repeat Interval |
|
FC |
Not Applicable |
Not Available |
Available |
Blank |
Computation of NSD: “Schedule Reset Basis” = “Actual Schedule Value”
|
Last Performed Date |
Due Date (NSD defined for the task in Aircraft/Component Maintenance Program component) |
Repeat Interval (Fixed or Floating) |
Next Scheduled Date (NSD) |
|
Not Applicable |
Available
|
Available |
Due Date + Repeat Interval |
|
Not Applicable |
Not-Available
|
Available |
Blank |
Computation of NSV: “Schedule Reset Basis” = “Actual Schedule Value”
|
T1-Parameter |
Due Date (NSD defined for the task in Aircraft/Component Maintenance Program component) |
Last Complied Value |
Repeat Interval (Fixed or Floating) |
Next Scheduled Value (NSV) |
|
FH |
Available |
Not Applicable |
Available |
Last Complied Value + Repeat Interval |
|
FC |
Not-Available |
Not Applicable |
Available |
Blank |
Scenario 4: Task with Update Basis (as defined in maintenance programs)
Computation of NSD; Update Basis = “Actual”, “Schedule” or “Time Window”
|
Repeat Interval (Fixed or Floating) |
Last Complied Date |
Next Scheduled Date (NSD) |
|
Available |
Available |
Last Performed Date + Repeat Interval |
|
Available |
Not Available |
Blank |
Computation of NSV; Update Basis = “Actual”
|
T1-Parameter |
Last Complied Value |
Repeat Interval (Fixed or Floating) |
Next Scheduled Value (NSV) |
|
FH |
Available |
Available |
Last Complied Value + Repeat Interval |
|
FC |
Available |
Not Available |
Blank |
Computation of NSV; Update Basis = “Schedule”
|
T1-Parameter |
Last Complied Value |
Repeat Interval (Fixed or Floating) |
Actual Compliance Value |
Next Scheduled Value (NSV) |
|
FH |
Complied before negative tolerance limit or after NSV |
Available |
Available |
Actual Complied Value + Repeat Interval |
|
FC |
Available |
Complied between negative tolerance limit or after NSV |
Available |
Last Complied Value + Repeat Interval |
|
EH |
Available |
Available |
Not-Available |
Blank
|
Computation of NSV; Update Basis = “Time Window”
|
T1-Parameter |
Last Complied Value |
Repeat Interval (Fixed or Floating) |
Actual Compliance Value |
Next Scheduled Value (NSV) |
|
FH |
Complied within negative tolerance and or positive tolerance limits |
Available |
Available |
Actual Complied Value + Repeat Interval |
|
FC |
Available |
Complied beyond negative tolerance an positive tolerance limits |
Available |
Last Complied Value + Repeat Interval |
|
EH |
Available |
Available |
Not-Available |
Blank
|