performance criteria, or modifies design as required. Manufacturing Part loader malfunctions, Heat treater is blamed for Product design manager is hase and a small fraction of the poor process control inspired to perform detailed load does not experience failure mode and effects proper thermal cycle, but analysis(FMEA) in presence none of the bad ones are in of mechanical. materials the test group manufacturing, and maintenance personnel, and Service phase Part is subject to Hardness data can be Product design manager unexpected and easy to misinterpret ired to perform detailed undetected heat, which leading to assignment of FMEA in presence of changes the hardness the same likely cause mechanical. materials listed above. if manufacturing, and microstructure analysis is maintenance personnel, and not included customers Avoiding Errors. The failure analyst needs to be aware that sorting out the causes of failures can cause economic and noneconomic(e.g, psychological) consequences to particular individuals or companies who are implicated for carelessness, negligence, simple ignorance, or other errors or omissions. Thus, it is important to avoid mistakes, as they could cause as much harm as, or more harm than, the original failure Analytical mistakes may be technical in nature, such as an incorrect measurement of a mechanical prope Analytical mistakes may also be subtle. An example may be not questioning a suspicious hardness composition data point. Another example error in judgment of the significance of something that normally a minor detail. If this causes one to overlook things that bear close scrutiny, an incorrect conclusion may be drawn. Making sure that all relevant details are examined can help point to a clear conclusion and is a key to competent failure analysis work In situations that involve loss of life, human injury, or large economic damage, professional analysts should be very careful to do work only within their areas of competence. It is important to know the limits of one 's own knowledge and to know when help is needed. In fact, input from people from many areas will probably be involved in all but the most basic physical-cause investigations. If the failure involves complex interactions of latent factors, an interdisciplinary approach is generally required to prepare prevention strategy recommendations Fear of overlooking important details is probably the biggest reason that many experienced analysts refuse to perform failure analysis work unless they are given the time and budget to do a complete investigation. It is very easy to draw the wrong conclusions if one does not consider the "big picture" from multiple angles. A broad view is more likely to lead to a coherent conclusion or set of conclusions. To emphasize this important point again, a failure analysis must include an evaluation of the consistency of results from different tests or analytical methods. A single test result does not constitute a legitimate foundation for a failure analysis. Other common pitfalls in failure investigations suggested by Dennies(Ref 3)include Jumping to conclusions Not understanding the problem Not understanding how the failed system is supposed to operate Not considering all possible failure causes Tearing system apart without a developed plan We need to tear it apart as soon as possible Failing to follow through Not asking for help Thinking it is so easy to do Destroying evidence due to lack of plar Failure analysis is a profession that is rarely perfected in a given individual, and even experienced practitioners should remain aware of these potential pitfalls. It is also important to understand that failure analysis is not(ref 3) Thefileisdownloadedfromwww.bzfxw.comperformance criteria, or modifies design as required. Manufacturing phase Part loader malfunctions, and a small fraction of the load does not experience proper thermal cycle, but none of the bad ones are in the test group Heat treater is blamed for poor process control. Product design manager is inspired to perform detailed failure mode and effects analysis (FMEA) in presence of mechanical, materials, manufacturing, and maintenance personnel, and customers. Service phase Part is subject to unexpected and undetected heat, which changes the hardness Hardness data can be easy to misinterpret, leading to assignment of the same likely cause listed above, if microstructure analysis is not included. Product design manager is inspired to perform detailed FMEA in presence of mechanical, materials, manufacturing, and maintenance personnel, and customers. Avoiding Errors. The failure analyst needs to be aware that sorting out the causes of failures can cause economic and noneconomic (e.g., psychological) consequences to particular individuals or companies who are implicated for carelessness, negligence, simple ignorance, or other errors or omissions. Thus, it is important to avoid mistakes, as they could cause as much harm as, or more harm than, the original failure. Analytical mistakes may be technical in nature, such as an incorrect measurement of a mechanical property. Analytical mistakes may also be subtle. An example may be not questioning a suspicious hardness or composition data point. Another example is an error in judgment of the significance of something that is normally a minor detail. If this causes one to overlook things that bear close scrutiny, an incorrect conclusion may be drawn. Making sure that all relevant details are examined can help point to a clear conclusion and is a key to competent failure analysis work. In situations that involve loss of life, human injury, or large economic damage, professional analysts should be very careful to do work only within their areas of competence. It is important to know the limits of one's own knowledge and to know when help is needed. In fact, input from people from many areas will probably be involved in all but the most basic physical-cause investigations. If the failure involves complex interactions of latent factors, an interdisciplinary approach is generally required to prepare prevention strategy recommendations. Fear of overlooking important details is probably the biggest reason that many experienced analysts refuse to perform failure analysis work unless they are given the time and budget to do a complete investigation. It is very easy to draw the wrong conclusions if one does not consider the “big picture” from multiple angles. A broad view is more likely to lead to a coherent conclusion or set of conclusions. To emphasize this important point again, a failure analysis must include an evaluation of the consistency of results from different tests or analytical methods. A single test result does not constitute a legitimate foundation for a failure analysis. Other common pitfalls in failure investigations suggested by Dennies (Ref 3) include: · Jumping to conclusions · Not understanding the problem · Not understanding how the failed system is supposed to operate · Not considering all possible failure causes · Tearing system apart without a developed plan: “We need to tear it apart as soon as possible.” · Failing to follow through · Not asking for help · Thinking it is so easy to do · Destroying evidence due to lack of planning Failure analysis is a profession that is rarely perfected in a given individual, and even experienced practitioners should remain aware of these potential pitfalls. It is also important to understand that failure analysis is not (Ref 3): The file is downloaded from www.bzfxw.com