Building the System Hierarchy

The items that you add to an MPC project for aircraft systems and powerplant analysis are arranged in a tree-based system configuration called the system hierarchy. To access the configuration, click the System Hierarchy tab on the System panel.

The System Hierarchy tab in MPC works in a manner similar to other ReliaSoft applications (such as XFMEA or RCM++) except that there can be no more than four levels in the hierarchy (system, subsystem, sub-subsystem and part), and the first two levels must be selected from a predefined list of ATA chapters (systems) and sections (subsystems) that are stored in the database.

Each item has properties associated with it, which are viewed and edited on the Properties tab of the Analysis panel when the item is selected.

Available Columns

The following columns are displayed in the system hierarchy:

  • ATA # displays the item number. For systems and subsystems, this is the ATA-assigned number. For sub-subsystems and parts, this is the value given in the item properties.
  • Description displays the item name and/or description of the system or part.
  • MSI displays an MSI icon if the item has been identified as a maintenance significant item that requires functional failure analysis. According to the MSG-3 guidelines, an item will be marked as an MSI under the following conditions:
    • It is a system, subsystem or sub-subsystem. (Parts cannot be flagged as MSIs.)
    • It is the lowest level (above part) in its branch of the system hierarchy that has a Yes answer to at least one of the MSI selection questions.

Note: If you select the Flag parts with 'yes' answer(s) for MSI questions option in the MPC Application Setup, then the column will display a square icon, , for each part that has answered "Yes" to at least one MSI question. This makes it easier to see which parts may need extra attention.

  • Status Updates displays if the item contains any status update notes.
  • Attachment displays a paper clip icon if one or more files or URLs have been attached to the corresponding item. It displays if a Description and Operation (D&O) document is one of the attached files.
  • Flag displays a flag for the item, if desired. The available flags are: Complete (indicated by a green flag), In Progress (indicated by a yellow flag) and Incomplete (indicated by a red flag). In all ReliaSoft applications, flags are displayed in the interface only and do not affect analysis results or reports.
  • User Access displays an icon when the item is inaccessible. (See Status Indicators.)
    • If the item is in use by another user, an in use icon will be displayed. Point to the icon to display the name of the user who is accessing the item.
    • If you do not have the item permissions needed to edit the item, a restricted access icon will be displayed.
  • F-F-E-C Analysis displays if a functional failure analysis has been created for the MSI.

Adding Systems and Subsystems

For compliance with the ATA numbering guidelines, the available system and subsystems have been predefined for the database. (See Managing ATA Chapters.)

  • To add a new system, choose Systems > Add > Add System(s).

  • To add a new subsystem, select a system and then choose Systems > Add > Add SubSystem(s).

Both commands open windows that display the list of systems/subsystems that have been predefined for this database. Use the check boxes to select one or more items to add to the system configuration and click OK.

Note that each system/subsystem can be used only once per project. So if the item already exists in the current system configuration, the text will be grayed out and you will not be able to select it.

Adding Sub-subsystems and Parts

Sub-subsystems and parts are not predefined for the database. Instead, you have the flexibility to create these records as needed for your particular analysis.

  • To add a new sub-subsystem, select a subsystem and choose Systems > Add > Add SubSubSystem.

  • To add a new part, select the parent item (can be a system, subsystem or sub-subsystem depending on which level will be defined as the MSI) and choose Systems > Add > Add Part.

Note the following:

  • The command(s) to add subsystems and/or sub-subsystems will be disabled if:
    • At least one part has already been defined for the parent item. Parts can be added under any type of record (system, subsystem or sub-subsystem), but they must always be the lowest level in any particular branch of the hierarchy.
    • You have answered "Yes" to at least one MSI selection question for the parent item or you have defined at least one function in the F-F-E-C for the parent item. Both of these actions signal that the parent item is an MSI.
  • Because of the ATA numbering guidelines, you cannot add more than 9 sub-subsystems for the same parent. The ATA numbers for all sub-subsystems must begin with the same number as the parent. For example, if the subsystem’s ATA number is 10, you can define sub-subsystems with any or all of the following numbers: 11, 12, 13, 15, 15, 16, 17, 18 or 19.
  • There is no limit to the number of parts that you can add for the same parent, and you can use any number for the # field as long as it is unique among the parts associated with that item.

Deleting

To delete an item from any MPC hierarchy, select the hierarchy item and press DELETE. The hierarchy item will be deleted, along with all dependents and all associated attachments. There is no undo for deleting an item or the entire hierarchy.

Cutting/Copying

You can cut or copy items in any MPC hierarchy and paste them to the same project or to another project within the same database. (Please note that if you want to share hierarchy items between different databases, you must use the import/export functionality instead.) To select multiple hierarchy items for cut or copy:

  • Click the first hierarchy item and then press CTRL and click additional hierarchy items at the same level of the hierarchy.

or

  • Click the first hierarchy item, then press SHIFT and click another hierarchy item to select all hierarchy items at the same level of the hierarchy between and including the two.

After you select the hierarchy items, you can use the standard keyboard shortcuts for cut/copy (CTRL+X and CTRL+C) or you can choose Home > Clipboard > Cut and Home > Clipboard > Copy. When a hierarchy item is cut or copied, all dependents will also be cut or copied, along with any attachments.

Pasting

To paste items that you have cut or copied from any MPC hierarchy, press CTRL+V or choose Home > Clipboard > Paste. Note the following:

  • For the top two levels in the hierarchy (i.e., systems/subsystems, structures/substructures or major zones/major sub-zones), each item can be used only once per project. If an item with the same number already exists within the project you are pasting to, you will be prompted to decide if you want to replace the existing hierarchy item or cancel.

  • If a hierarchy item is cut or copied but then deleted from the project, the copied data will also be deleted from the Clipboard. In addition, once a hierarchy item has been cut or copied, any edits that are made to the original will also be applied to its copy in the Clipboard. In other words, if there are changes to the original hierarchy items after you cut/copy them but before you paste them somewhere else, this will affect the data that can be pasted. Also note that you will not be able to cut or copy a hierarchy item in a project that is locked by another user.

Importing

It is easy to import any entire hierarchy (or selected items) from any project in the same database or another selected database. (See Importing MPC Hierarchies Between Projects.)

Related Topics and Links