TRAX MANUALS > Technical Records > Technical Records Module > Technical Records, Update Menu > Defect Report > Defect Report Detail > Defect Report Detail, Defer Tab > Defect Due Date Formulas

This document details the formula change for Defect Due Date calculation in the TRAX app after version 15 service pack 9. The first section gives a breakdown of each formula (Pre/Post v15 SP 9) and the second half illustrates an example of the formula being calculated. 

Pre TRAX Service Pack 9 Formula

Before TRAX 15 SP 9, Defect Due Dates were calculated using the formula below:

(Scheduled Cycles) - (Actual Cycles since Defer Date) = Remaining Cycles / (AC Schedule Mean)

Post TRAX Service Pack 9 Formula

After TRAX 15 SP 9, Defect Due Dates are calculated using the formula below:

(Scheduled Cycles) - (Actual Cycles since Defer Date) = Remaining Cycles

Planning will then deduct time or cycles from future flights in the A/C Flight Schedule, and then forecast from the last scheduled arrival flight date if any remaining time is left over.

(Last Scheduled Arrival Flight Date) + ( {Remaining Cycles after further subtraction} / AC Schedule Mean) = Forecast Due Date

Note: If the remainder becomes 0 during the total subtraction, the Due Date will be the scheduled flight date from which the calculation was subtracted.

The following A/C flight data will be used for this example.

Note: A Rolling Average is not used in this example since this variable varies for each operator.

Note: The switch AC/SCHED is set to No.

The Z record for the A/C is as follows.

The Aircraft Flight Log Report is as follows.

The following Defect is created/deferred by 10 Cycles.

A second Defect is created/deferred by 48 Hours.

TRAX 15 Pre-SP 9 Calculation

The following is a breakdown of the data and formula using Defect JE with a schedule of 10 Cycles.

• Schedule Cycles: 10
• Actual Cycles: 0
• Actual Cycles since defer: 0
• Today’s Date: 05/15/2024
• Defer Date: 05/14/2024 at 17:21
• AC Schedule Mean Cycles: 2.00

Formula:

(Scheduled Cycles) - (Actual Cycles since Defer Date) = Remaining Cycles / (AC Schedule Mean)

Today's Date + Result = Forecast Due Date

Calculation:

(10 – 0) = 10 / (2) = 5 Days

05/15/2024 + 5 Days = 05/20/2024 Forecast Due Date

The calculation is accurate.

The following is a breakdown of the data and formula using Defect JE-2 with a schedule of 48 Hours.

• Schedule Hours: 48
• Actual Hours: 1
• Actual Hours since defer: 1
• Today’s Date: 05/15/2024
• Defer Date: 05/14/2024 at 00:00
• AC Schedule Hours Mean: 15.00

Formula:

(Scheduled Hours) - (Actual Hours since Defer Date) = Remaining Hours / (AC Schedule Mean)

Today's Date + Result = Forecast Due Date

Calculation:

(48) - (1) = 47 / (15) = 3.133 Days

05/15/2024 + 3.133 Days = 05/18/2024 Forecast Due Date

The calculation is accurate.

TRAX 15 Post-SP 9 Calculation

The following is a breakdown of the data and formula using Defect JE with a schedule of 10 Cycles.

• Schedule Cycles: 10
• Actual Cycles: 0
• Actual Cycles since defer: 0
• Today’s Date: 05/15/2024
• Defer Date: 05/14/2024 at 17:21
• AC Schedule Mean Cycles: 2.00

Formula:

(Scheduled Cycles) - (Actual Cycles since Defer Date) = Remaining Cycles

Planning will then deduct time or cycles from future flights in the A/C Flight Schedule, and then forecast from the last scheduled arrival flight date if any remaining time is left over.

(Last Scheduled Arrival Flight Date) + ( {Remaining Cycles after further subtraction} / AC Schedule Mean) = Forecast Due Date

Calculation:

(10 – 0) = 10 Cycles

Planning will then deduct time or cycles from future flights in the A/C Flight Schedule, and then forecast from the last scheduled arrival flight date if any remaining time is left over.

Cycles Remaining – (Sum of cycles/hours from future flights beyond today’s date in scheduled depart date ascending order)

10 - (1 cycle from flight 29 leg 1) = 9

9 - (1 cycle from flight 44 leg 1) = 8 Cycles Remaining

(8/2) = 4 Days

(05/18/2024) + 4 Days = 05/22/2024 Forecast Due Date

The calculation is accurate.

The following is a breakdown of the data and formula using Defect JE-2 with a schedule of 48 Hours.

• Schedule Hours: 48
• Actual Hours: 1
• Actual Hours since defer: 1
• Today’s Date: 05/15/2024
• Defer Date: 05/14/2024 at 00:00
• AC Schedule Hours Mean: 15.00

Formula:

(Scheduled Hours) - (Actual Hours since Defer Date) = Remaining Hours

Planning will then deduct time or cycles from future flights in the A/C Flight Schedule, and then forecast from the last scheduled arrival flight date if any remaining time is left over.

(Last Scheduled Arrival Flight Date) + ( {Remaining Hours after further subtraction} / AC Schedule Mean) = Forecast Due Date

Calculation:

(48 – 1) = 47 Hours

Planning will then deduct time or cycles from future flights in the A/C Flight Schedule, and then forecast from the last scheduled arrival flight date if any remaining time is left over.

Hours Remaining – (Sum of cycles/hours from future flights beyond today’s date in scheduled depart date ascending order)

47 - (9 hours from flight 29 leg 1) = 38

38 - (4 hours from flight 44 leg 1) = 34 Hours Remaining

(34/15) = 2.3 Days

(05/17/2024) + 2.3 Days = 05/19/2024 Forecast Due Date

The calculation is accurate.