Engineering Services


Failure Modes and Error Analysis and Failure Modes, Effects and Criticality Analysis are two tools used in aerospace, the military and automotive industries to gauge the robustness of a design. FMEA/FMECA are bottoms up analyses that start with a hypothesis that one device has failed, then determines how that failure would affect the circuits around the failure as well as its impact on the system. This analysis is important when concerning system safety, as in nuclear power plants, military weapons and manned space missions. It is used to find single point failure that could cause a catastrophic event including: loss of life, loss of mission, or another major safety violation.

The analysis may be performed to the military standard Mil-Std-1629. In addition, the analysis may be initiated at either the system level or the piece part level. *See: FMEA_EXAMPLE

FXO Inc. has extensive experience in creating a functional FMEA from schematic designs.  FXO Inc. consultants have extensive experience in compiling FMEA and FMECA documents on aerospace and avionics equipment.



Fault Tree Analysis is a top-down analysis of a design. It is a graphical representation of the components of the system and how their potential failures contribute to a particular failure. This can be evaluated quantitatively or qualitatively.  FXO uses Relex Software in computing Reliability Prediction, FMEA and Fault Tree.



This analysis is used to prove that a design will meet all critical specifications while operating over its required environment and lifetime. FXO Inc. can create a worst case analysis for an existing design or perform a Design Review on your analysis.  We have used both Extreme Value Analysis and Root Sum Squared analysis to guarantee operation of spaceborne electronics.



This analysis is usually started after an anomaly has occurred in either the testing or the operation of an instrument. FXO Inc. will create a Fault Tree of the system that was in place in order to determine a root cause of the failure. FXO Inc. engineers have been consulted to analyze a spacecraft component that had failed in space.  These engineers created a final report on the most likely causes of the failure. 

Example: FXO Inc. was asked to analyze a test anomaly on a flight computer during ground test.  The failure looked like it could have been caused by failures on any of three flight boards.  In that case, it may have been prudent to never use this high value asset and try to build a new unit.  FXO found the cause of the anomaly and tracked it down to the only possible chip on one board that was the cause.  This chip was replaced and the flight unit is in the process of re-qualification.


The latest tools are used to solve reliability predictions, FMEA, and Fault Trees.

FXO can perform Single Events and Effects Analysis (SEEA) on your spaceborne hardware.



FXO Inc. can solve test software issues. We will reuse ATLAS Code or convert ATLAS software to software compatible with your upgraded test system.  FXO Inc. can write specific programs to speed up the writing and troubleshooting of your test code.  FXO Inc. has written helper programs to Renumber and Syntax Check ATLAS code.  This aids in opening up statement numbers to allow other code to be inserted.  FXO Inc. can test your ATLAS code or hardware using Instrumentation Engineering’s IE System 390 MATS machine.  Fran O’Connell has over 20 years experience in testing hardware on this piece of test equipment as well as designing test fixtures and add on circuits to enhance the IE System 390 MATS machine (See

FXO Inc. can perform the migration from HP BASIC legacy systems to C-Based systems or HT BASIC systems using the latest PC. 

LabView: FXO Inc. can develop a test using LabView to test your digital or analog electronics.  FXO Inc. has used LabView to simulate spacecraft circuits in order to test electronic boxes to guarantee that the new designs will meet the spacecraft timing and voltage requirements.  (see:


FXO Inc. can help solve most test related failures.   We have had 100% success in finding the root cause of the problem and solving it.

Example:  We were called in to repair a rack of equipment that performs a simulation of the bus component of a Mars orbiting spacecraft.  Everything was going wrong in the simulation.  The simulation was shutting down.   The actual spacecraft was being prepared to make a maneuver and the simulation could not be run.  It looked like a nightmare scenario.  FXO was called into troubleshoot. Within one day, we found an open connector that was supposed to be mated to a VME/VXI I/O board.  This was easily repaired.  



FXO Inc. can design new hardware and perform worst case speed analysis, FMECA, power analysis, as well as prepare a complete data package.    We have the resources to simulate our digital designs as well as PSPICE the analog designs.  We have experience in making upgrades and redesigns to existing systems.  

FXO Inc. can design new hardware and software to work with embedded microcontrollers.  We are presently (February 2005) working on the design using the Tern microcontroller (AMD 186 based processor) to control a science experiment using a C program.



FXO Inc. will upgrade or repair your ancient hardware. 

We maintain special purpose spacecraft simulation equipment.  This unit contains the flight computers that are used on the weather satellite as well as boards that model the other systems on the weather satellite.  A models computer and user interface allow software engineers to develop changes to the flight software on the spacecraft as necessary.  Some spacecraft have been in operation 20 years and as different systems fail, the software must be changed to work without these systems to keep the spacecraft oriented correctly.

We successfully upgraded a piece of test equipment to test the spacecraft computer as follows:

o   Troubleshoot of a test rack of equipment that was in storage for 10 years. 

o   Removed of the Tecmar Computer (8086 based, S-100 Bus with CP/M operating system)

o   Integrated of a Pentium III ruggedized personal computer running Windows XP operating system

o   Upgraded from CPM Pascal software to Microsoft C with plug and play digital I/O cards

o   Made Mechanical modifications of some of the hardware.

We completed this design on time and within budget.  We can do that for you too!


We successfully completed an upgrade from an HP-85 based control computer  (HP-85B) to a Pentium IV computer from ACME Portable.  The HP BASIC software has been converted to HT BASIC.  An IEEE-488 card is controlling an HP3561A Network Analyzer and HP5316A Frequency Counter to take measurements on a highly reliable spacecraft reaction wheel.  The operator interface was modified from typing numerous commands to an easy to use Windows graphical user interface.

HT BASIC is designed by TransEra Corp.  see:

The Pentium Computer is from ACME Portable Machines Inc. at:

In addition, we replaced an X-Y plotter with the same computer and A/D converter.  The computer will read the X-Y plot inputs (-10V to +10V on the Y-axis and -1V to +1V on the X-Axis).  From the input voltage, the output plot will be captured on the computer screen.  When the plot has been satisfactorily captured, the plot image is printed to an HP ink jet printer.  The software makes allowances for the “pen” to be lifted during the measurement so to capture multiple test images.

The A/D converter modules are designed by Scientific Solutions.  See:


VME/VXI components

ATLAS Test systems

Motorola 68000, 68020 firmware design, upgrade

Mil-Std-1750A microprocessor firmware design, upgrade

Board level Special Test Equipment (STE)

Box level STE

HP BASIC systems migration to HT BASIC systems


Request Quote or Rough Order of Estimate from  FXO Inc. on your design or upgrade.


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