M-TOSS Numbering System

Task Oriented Support System (TOSS) is a numbering system used in ATA iSPEC 2200.

TOSS numbering system is divided into 3 groups:

• Maintenance Task Oriented Support System (M-TOSS)
• Aircraft Maintenance Task Oriented Support System (AM-TOSS)
• Jet Engine Maintenance Task Oriented Support System (JEM-TOSS).

M-TOSS numbering system has seven (7) elements:

1. First Element – System/Chapter
2. Second Element – Sub-system/Section
3. Third Element – Units of Subsystem/Subject
4. Fourth Element – Fourth element is called as functional code
5. Fifth Element – Fifth element is called unique or sequential identifier. It is provided to create unique numbers for all tasks and subtask which are similarly numbered through the first four elements. Task number is numbered from 801-999 and subtask numbered from 001-800
6. Sixth Element – Sixth element is called as configurational code
7. Seventh Element – Seventh element is called as customer code.

Example of a Task Numbering System:

25-28-40-410-803-A01-CC1

Find the presentation in the below YouTube link-