mtbf (mean time between failures) calculations of an assembly

Elsmar Forum Sponsor
#4
For calculating MTBF for a PCI card, I would be using MIL-217F N1/2 parts count method, using Ground Benign. Worst case part ambient temp will be 40 degrees C.

Is 40 C a good temperature or should I scale back to 30 C?
 

Miner

Forum Moderator
Staff member
Admin
#5
Depends on the application and to what temperatures the PCB is exposed. Not just external ambient, but internal to device ambient, and whether cooling fans or heat sinks are part of the equation.
 
#6
Is there a company out there that if I give them my BOM they will do the MTBF calculations for me without charging major bucks?
 

Steve Prevette

Deming Disciple
Staff member
Super Moderator
#7
Is there a company out there that if I give them my BOM they will do the MTBF calculations for me without charging major bucks?
I'm sure there are folks here (including myself) that could do the calcs. But we would need much more than the Bill of Materials. We'd need to know the application and the specifications, the failure modes and rates that you have identified, the way the components work together in the system and interdependencies between them.

For example, let's take the highest failure rate component that you've referenced in the first email. If it only can fail if another component fails which isn't likely to fail, or if there is another component in parallel it, or perhaps the operating environment doesn't stress the component enough to cause it to fail, then you have a whole 'nother answer.
 
#8
There are companies, (probabilistic software) that offer this service. Cost is 2500. per board. Too much monies, need someone else, know of any?
 

Jim Wynne

Staff member
Admin
#9
There are companies, (probabilistic software) that offer this service. Cost is 2500. per board. Too much monies, need someone else, know of any?
There might be companies that are willing to separate you from your money and give you a theoretical or hypothetical MTBF number, but unless there's actual ground-truthing and testing under load in the assembly, you don't have anything that's necessarily meaningful. What you need is a person who is expert in reliability analysis.
 

Miner

Forum Moderator
Staff member
Admin
#10
Let's start at the beginning. What is your goal? Why do you need the MTBF?

Is this a customer request? Internal request? Or is your goal simply to improve the reliability of the product?

If your goal is to improve the reliability, forget MTBF. You already know that the fan is the weakest link, so improve it and you do improve the product. Ford does not worry about MTBF or reliability testing, they focus on DFMEA/PFMEA and improving the demonstrated weakest links.
 
Thread starter Similar threads Forum Replies Date
S Calculating MTBF (Mean Time Between Failures) for the whole Production Unit Reliability Analysis - Predictions, Testing and Standards 2
S Mean Time Between Failures (MTBF) - SN 29500 Standards? Various Other Specifications, Standards, and related Requirements 5
S Calculating MTBF (Mean Time Between Failures) of different Electronic Components. Reliability Analysis - Predictions, Testing and Standards 16
K MTBF (Mean Time Between Failures) Calculation Reliability Analysis - Predictions, Testing and Standards 4
J Graphing MTBF (Mean Time Between Failures) or Reliability Data of a System Reliability Analysis - Predictions, Testing and Standards 1
M Mean Time Between Failure (MTBF) Data for a New Design Customer and Company Specific Requirements 9
M MTBF (Mean Time Between Failures) - Seeking help Statistical Analysis Tools, Techniques and SPC 1
A Mean Time Between Failures (MTBF) Basics - Thoughts on Product Life Cycles Preventive Action and Continuous Improvement 6
R Regression for MTBF (Medical Device: Repairs vs Install Base) with Reliability Data Reliability Analysis - Predictions, Testing and Standards 16
M Calculating MTBF for plug-in PCI cards Reliability Analysis - Predictions, Testing and Standards 2
S Definition MTBF and MCBF Correct Definitions Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 5
S Reliability Calculation - MTBF/MTTF for Static Mounts of Rail Industry Reliability Analysis - Predictions, Testing and Standards 2
S MTTR - MTBF - Machine History Card template form Manufacturing and Related Processes 16
V Plotting MTBF for More Systems in a Single Chart using Meridium 3.4.2 Software Reliability Analysis - Predictions, Testing and Standards 2
M Typical values of MTBF for Optical Avionic Networks Reliability Analysis - Predictions, Testing and Standards 1
Q Best consultant for Predicted MTBF consulting service using Telcordia standard Reliability Analysis - Predictions, Testing and Standards 3
C Is tool wear monitoring and MTBF of machine parts considered as PdM? Manufacturing and Related Processes 6
B Reporting 24/7/365 Reliability Data - MTBF Data for Customer Advertising Reliability Analysis - Predictions, Testing and Standards 6
B MTBF calculations - Three student homework problems Reliability Analysis - Predictions, Testing and Standards 10
E Calculating the MTBF for an assembly, Failure and Rework Prediction Reliability Analysis - Predictions, Testing and Standards 6
J How to calculate MTBF of a system based on subcomponents Reliability Analysis - Predictions, Testing and Standards 14
D The difference between MTBF and MTBWSF and how to calculate MTBWSF of a system Reliability Analysis - Predictions, Testing and Standards 2
B Calculating a Standard Deviation with respect to MTBF Reliability Analysis - Predictions, Testing and Standards 1
I The Anomaly of Calculating MTBF from Reliability Reliability Analysis - Predictions, Testing and Standards 1
J Calculating the overall MTTR for an MTBF of 476, given four subsystems Reliability Analysis - Predictions, Testing and Standards 1
R MTBF to DPPM Calculation Based on the Unit's Typical Working Hours Reliability Analysis - Predictions, Testing and Standards 9
E Parallel RBD's (Reliabilty Block Diagram) help - Reliability & MTBF Reliability Analysis - Predictions, Testing and Standards 10
J Calculating MTBF for an electrical component Reliability Analysis - Predictions, Testing and Standards 8
W Applying MTBF and MTTR to Maintenance Misc. Quality Assurance and Business Systems Related Topics 2
T What does AS9100 mean when it says you must establish a process to do X? AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 8
B General Motors and Honda Alliance - What does this mean to suppliers? IATF 16949 - Automotive Quality Systems Standard 3
A What does this sentence "this symbol shall be used in the orientation shown" mean in ISO 780:2015? Other Medical Device Related Standards 4
K What is mean by Oxygen Rich Environment as per the IEC 60601-1 clause no 11.2.2 IEC 60601 - Medical Electrical Equipment Safety Standards Series 5
M Definition Open Audit - What does an Open Audit mean? Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 3
S EU MDR Annex XIV - Clinical Evaluation Plan - What do these methods mean? EU Medical Device Regulations 12
P What does UPH/m² mean? Quality Tools, Improvement and Analysis 3
L "IATF-Compliant" IATF 16949:2016 certification? What does this mean? IATF 16949 - Automotive Quality Systems Standard 13
E Circled-Z symbol on a syringe — what is it for, what does it mean? China Medical Device Regulations 21
I What does "Class" mean in an FMEA? FMEA and Control Plans 16
Q What does % study variation of 20% mean in GRR? Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 17
J GHTF Incidents - What does unlabeled and labeled mean? Japan Medical Device Regulations 9
S When a deviation is opened but what does it mean to close a deviation? Misc. Quality Assurance and Business Systems Related Topics 1
A Definition Intended Results - What does "Intended Results" mean? Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 4
O What does "Gap" and "Flush" in ASME Y14.5 mean? Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
qualprod ISO 9001 Cl. 4.1 and 4.2 - What does monitoring and review mean? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 13
J What does "factional and failure dependencies“ mean? FMEA and Control Plans 1
A What does 8.2.2.1, Determining the requirements related to products and services,mean IATF 16949 - Automotive Quality Systems Standard 1
E Uncertainty of Mean - Test rig that measures water temperatures Measurement Uncertainty (MU) 3
J What does "If required by the customer" mean? IATF 16949 - Automotive Quality Systems Standard 4
J What does "Corporate stewardship" mean? IATF 16949 - Automotive Quality Systems Standard 6

Similar threads

Top Bottom