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  EDITORIAL A Process-Based Approach in Failure Analysis George A. Pantazopoulos Submitted: 27 June 2014   ASM International 2014 The aim of this editorial, linked to a previous one [1], is todiscuss and share a fundamental thinking process pertain-ing to the design of failure analysis procedure. The subjectof organization of failure investigation is comprehensivelypresented in the excellent Ref. [2], highlighting alsodetails, examples, and applications from the real world of industry and engineering. The holistic and quality-basedapproach is an essential element of failure analysis inves-tigation to reach high performance and success to the presetgoals, as it is in line to worldwide-adopted quality man-agement systems, such as ISO 9001.A primary approach based on process-design may serveas a guide or work instruction for failure analysis. The useof flowchart is highly advised in quality systems and pro-cess development. A representative and indicative exampleis shown in Fig. 1, and it has many analogies to the famousPlan-Do-Check-Act (PDCA) cycle of the Quality Guru W.Edwards Deming (1900–1993).The main steps of such process can be summarized asfollows:1.  Submission of the inquiry for failure analysis . In thisstage, the inquiry is submitted and registered in order tobe properly processed, similarly to a sales inquiry.2.  Background information and review of the work requirements . This is a very critical step for thedetermination of the needs for resources (humanskillsets and equipment), in order to provide a reliableand high quality level service. Legal requirements,safety issues, quality systems certifications, externalaudits, etc. should also be considered as significantaspects of the entire work. The identification of theminimum requirements needs very frequently therealization of face-to-face discussions, interviews of the involved personnel, meetings, and teleconferencesthat stretch the timeline and the incurred costs. Theresult of the review process may lead to a preliminarycost estimation that is necessary to be presented formanagement approval.3.  Management approval . As it is always required, amanagement decision is absolutely mandatory to pro-ceed further to the work planning, considering also theother priorities. In case of an economic offer, cus-tomer’s official consensus concerning technicalspecifications, time, and cost is crucial to initiate thework.4.  Allocation of resources and work scheduling . For aneffective planning, a team leader must be appointed bythe management team, and a start-up meeting amongthe work team should be planned. Timeline and stagesof the failure analysis project, competencies of theinvolved team members and possibilities for outsourceactivities, delegation of responsibilities (who doeswhat?) … , are principal issues that are usually dis-cussed. Gantt charts could be the outcome of suchmeetings, especially for complex failure case studies.5.  Failure analysis investigation . This is in the main coreof the process, involving the technical stages of theinvestigation, starting from sampling or sample selec-tion. The sampling process, together with the properpreservation/maintenance of sensitive samples, is of vital importance for failure analysis. Improper samplingor destruction of sensitive samples may eliminate thechance to obtain conclusive evidence for the root-causeand ruin the entire project. For example, fracture G. A. Pantazopoulos ( & )ELKEME Hellenic Research Centre for Metals S.A., 252 PireausStreet, 17778 Athens, Greecee-mail:  1 3 J Fail. Anal. and Preven.DOI 10.1007/s11668-014-9853-z  Fig. 1  Flow-chart depicting the general aspects of failure analysis investigationJ Fail. Anal. and Preven.  1 3  surfaces, as very sensitive to oxidation or mechanicaldamage, unsuitable storage, or careless transportationmay cause irreversible damage, obliterating any sign orevidence of failure mechanism(s). Testing and evalu-ation of specimens using analytical techniques such asnon-destructive-testing (NDT), visual inspection, opti-cal microscopy, scanning electron microscopy andmicroanalysis, hardness/tensile testing, numerical sim-ulation, etc. are very common procedures utilized forfailure examination.6.  Assessment of the potential failure mechanism(s) . Thecritical review of the failure analysis (‘‘raw’’) data anddiscussion within the corresponding team are requiredto address the mechanism of failure—i.e., ‘‘how’’ thisfailure process occur? Via which mechanism or seriesof mechanisms? In practice and as a simplified view,the principal categories of mechanisms that play amajor role to engineering components’ operation are: ã  Instant mechanisms  mechanical overload coveringvarious loading modes (such as tensile, compres-sion, bending, torsion). ã  Progressive or time-dependent mechanisms (mostlymet in mechanical or machine components’ fail-ures)  creep, fatigue, corrosion, wear. ã  Combined/complex mechanisms  combining variousindividual mechanisms as shown above (e.g., cor-rosion-fatigue).The collection and assessment of experimental analysisevidence and logical (common sense) approach willeffectively lead to the identification of failure mecha-nism(s). Critical and objective thinking should prevail inthe assessment of the acquired evidence; secondarymechanisms and artifacts should be recognized andneglected. For example, contamination by corrosion sub-stance of the prior fracture surface could provokeconfusion regarding the main failure mechanism, leadingvery frequently to dangerous misinterpretations.7.  Assessment of the potential root-sources . Suggestion of the most plausible root-cause. This stage goes deeper tothe understanding of failure process and the interactedcauses—addressing the ‘‘why’’ the determined failuremechanism acted? Besides objectivity and impartiality,it requires profound knowledge on the product andprocess, technical expertise, intelligence, and ‘‘talent’’.Failure analysts should have the ability and analyticalskills to reconstruct the failure scene using a backwardthinking process, binding the  effect   with the  cause ( s ).Work team discussions and brainstorming are useful toidentify the list of possible root-sources based onlogical argumentation. The relationships of ‘‘cause-and-effect’’ could be vividly demonstrated by using quality-organizational tools and techniques, such as the well-known fishbone diagram (called also as ‘‘Ishikawadiagram’’). The evaluation of concurrent or interactingcauses should also be considered. For example, thestress concentration from geometric design of shaft filetradius together with the poor surface finish willmultiply the risk for fatigue failure. Main indicativecategories of cause(s) could be considered as follows: ã  Manufacturing ã  Design/specification ã  Testing/evaluation ã  Operation/maintenance ã  Installation ã  Organizational nature8.  Implementation of the most effective corrective actions .Suggestion of corrective actions comes as a naturalsequence of root-cause analysis, and it is required inquality management systems for continuous improve-ment. The possible corrective actions could be alsodiscussed in terms also of the projected efficiency andeffectiveness and the most appropriate ones should beselected based on objective arguments, also using timeand cost criteria. In the above example, the designrevision of the shaft fillet radius will lead to stresscalculations that minimize the loading levels belowfatigue limit, raising the safety factor and ensuringreliable operation of the component.9.  Evaluation of effectiveness of corrective action and decision for additional actions if required  . This stageleads to the confirmation of the problem solving processor to the revision of the action plan in order to achievethe preset target.10. Final report and closing of the case study . The reportsummarizes the various intermediate processes fol-lowed, the most important findings, and, of course, it iscommunicated among the involved work team mem-bers. This tends to constitute an element of the preciousbody of knowledge of the failure analysis learningprocess, documented, checked, and reviewed.  Lessonslearned   could also stand as an individual section or an‘‘epimythion’’ of the entire essay, reminding us, asmembers of the society/scientific community, andconsistently to failure analysis approach, that wealways tend to follow a self-improvement path. References 1. G. Pantazopoulos, Failure analysis, quality assurance, and businessexcellence. J. Fail. Anal. Prev.  13 (2), 119–120 (2013)2. D.P. Dennies,  How to Organize and Run a Failure Investigation (ASM International, Materials Park, 2005)J Fail. Anal. and Preven.  1 3
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