Recording usage

In Maintenix, usage is the amount of time that an item has operated, or the number of times that an item has undergone a specific situation.

A typical aircraft will have usage measured in many different ways, including flying hours (HOURS), cycles, landings and engine operating time (EOT). A take-off and landing sequence of an aircraft is one cycle. Tracking usage information is essential to the proper calculation of maintenance deadlines and activities.

Usage parameters and usage values

Each assembly includes a list of usage parameters tracked on each assembly. There are three usage values recorded in Maintenix:

  • Time Since New (TSN): The measure of usage (in any usage parameter) since the inventory was manufactured.
  • Time Since Install (TSI): The measure of usage (in various usage parameters) since the inventory item was installed into its current location.
  • Time Since Overhaul (TSO): The measure of usage (in any usage parameter) since the inventory item was last overhauled.
In Maintenix, TSN, TSO, and TSI are generic terms that can replace a series of previous terms, such as Cycles Since New (CSN) or Landings Since Overhaul (LSO).

TSN, TSO, and TSI are tracked against the current usage of inventory items.

The following historical values are displayed on a component's Inventory Details page, Historical tab, Installation sub-tab. These values are calculated on page load, as opposed to retrieved from the database, so any out-of-sequence edits to the records don't interfere with accuracy of the displayed values:
  • The TSI value upon removal or installation. For installations, the value is always 0. For removals, the value is the difference between the component TSN value at removal and at the most recent installation of the component.
  • The TSN value of the highest parent assembly.