Altium Extension – Frequently Asked Questions

Following are answers to FAQs that we received from our customers:

I do not see the latest extension in the "Purchased" extensions

In order to have access to the latest version you need to select the “Global installation service” from the extensions preferences:

  • From the top menu select Help, About, Extensions and updates
  • In the Purchased tab, click the gear, and select System, Installation
  • Select Global installation service
  • Select the update check frequency (we recommend to check every day)
  • Click OK

Note: If you cannot select the setting, please ask your IT to contact us at

I do not see the MTBF extension page

After installing the extension follow these steps:

  • Open a project
  • Open a schematic
  • From the top left menu select: File – New – fiXtress

Which MTBF calculation should I use?

The extension offers two built in MTBF calculators, each is in accordance with a different MTBF calculation standard:

MIL HDBK 217F2 Parts Count
This standard is mostly relevant to defense and aerospace equipment.
To use this method select the tab “Parts Count Prediction MTBF”.

Telcordia 332.3
This standard is mostly relevant to commercial equipment for telecom, medical and industrial purposes.
To use this method select the tab “Telcordia 332.3 MTBF Prediction”.


If you require MTBF calculation according to a different standard, please contact us as BQR offers software and professional services for additional standards.

What is the meaning of column “GBT” in Parts Count Prediction MTBF?

GBT is short for Gates, Bits or Transistors. MIL HDBK 217F2 appendix A defines the required parameter for each IC type:

IC Type Required input for GBT column
Gate / Logic Array Gates
Linear Microcircuits Transistors
Floating Gate Programmable Gates
Microprocessor Bits
Memories Bits
GaAs Active Elements

How do I use the components library?

Add components to library

The components library includes the library parameters for each part-number, e.g. component family, type etc.,

The library is saved whenever a calculation is done or the ‘Save Library’ button is clicked.

Note: During first library save you will be asked to select the library files location.


Reuse components library

When a new schematic is opened and the BOM is loaded, the BOM part numbers are checked against the library,

If a part-number is found in the library, the component parameters will automatically be assigned.

If you have additional questions, please let us know: