Introduction

Root Cause Analysis (RCA) and Failure Investigation are important tools in: 

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  • Product Complaint, 
  • mitigation activities, 
  • Failure Investigation,  
  • non-conformance, 
  • Risk Management,
  • hazard analysis,

and the basic foundation of a satisfactory Corrective And/or Preventive Actions (CAPA) system.  Root Cause Analysis is required to verify and validate the issues including data outliers.  These are often improperly and arbitrarily dismissed.   RCA is required in order to close the logic loops existing on:

  • corrective actions,
  • preventive actions, 

thus allowing a proper impact analysis before to decide any action.  Meaning that failure investigation and Root Cause Analysis are an important element of Current Good Manufacturing Practice (cGMP) regulations compliance, enforced by the US Food and Drug Administration.  When non adequately performed it becomes a key source of problems with respect to the norms of the Regulatory Agencies (i.e., FDA in the US, EFSA in the EU, etc.).   Companies’ resources are frequently scarce exactly in those activities that have the greatest positive effect to the Quality and Safety of their Product.   RCA is meant to reduce fire fighting, thus minimizing compliance problems also.   The expectations for meaningful Corrective And/or Preventive Actions, supported by: 

  • Root Cause Analysis,
  • results-driven Failure Investigation, 

addressing and resolving the hidden product problems, are really growing among the Regulatory Agencies.    Two significative examples are the FDA's QSIT, referred to equipments and the EU’s ISO 14971 thinked for the Device Risk Management.    A valid Corrective And/or Preventive Actions system requires defined failure investigation.  This includes a systemic Root Cause Analysis devoted to the true problem resolution.



Typical Root Causes for Repetitive Failures


1.  Conflict of interests

“Apart from SEC [US Securities and Exchange Commission] filings, companies are under no real obligation to tell the truth, the whole truth, and nothing but the truth, unless in sworn testimony” 

John Pike, director and founder of GlobalSecurity.org








Those few words above by John Pike, one of the world's leading experts on defense, space and intelligence policy, since 2000 director and founder of GlobalSecurity.org (US-based at Alexandria, Virginia) explain courageously the key-concept.   All of the others mere consequences, … effects or, more properly, …flying shrapnels.  We’ll take this sensitive subject from a certain distance, observing that the Food and Beverage Producer technical know-how implies Contractual Force.   Also meaning that the consequences of the Machinery failures and malfunctions, are always properly attributed to their true origin.  Then, implying full responsibility for the expenses related to the solution of the causes for Production inefficiencies and Quality pitfalls.   Front of failures or malfunctions, some of the most commonly heard answers: 







....."Impossible !”, 

.....”who said that !”,  

.....”one of your Operators did it”, 

.....”never happened before !”, 

.....”an effect of your Power Line” 

Answers intentionally leaving to the Bottler alone the onus, the expense of the demonstration that causes for the effects are external to its productive process and intrinsic to the Machinery.  Common examples are the disputed causes for the faults and/or malfunctions of the hardware, software and parameterisations controlling the machinery composing a Food and Beverage Packaging Line. Front of Machinery inefficiencies, in many cases the Bottler is proposed a conditioned check of the equipments.   Conditioned by the assumption of all charges which may arise for an audit of the Machinery, be paid by the Bottler if what is encountered after the Audit is a cause external to the Machinery.    This condition makes absolutely sense, but …who shall make the Audit ?     The question makes sense because an “Auditor” is not an “Arbitrator”.     The answer is: always and only staff named, acting and paid by the Part which sold and guaranteed the Machinery and the devices.   In other terms: 


            ...I sell you who is paid to take care of my interests...”


thus, forgetting the evident conflict of interest implicit in such proposal. 



2.  Low technical availability

Looking on the opposite side, the inner causes for inefficiencies, the equipments’ technical availability in the Food and Beverage Bottling Lines is one of the daily concerns of all Maintenance Departments. Also, this issue is more complex than it seems at first sight.  The key questions to be answered are: 

  1. what is a realistic target for technical availability ? 
  2. how can it be achieved ? 

A first approach implies the use of internal and external benchmark data, helping to determine realistic targets and, quite obviously, the maintenance program and the realization of that program have to be aligned to achieve those targets.  But, technical availability is only one of the components of the OEE (Overall Equipment Effectiveness).  To really improve the technical availability implies a recursive procedure, where all losses have to be registered and one-by-one analyzed.  




 Because of machinery and process complexity, the effects result frequently confused with the causes.  Imagine a function, of another function, of another function... and we are close to be still underestimating complexity.  That’s the reason for the relative difficulty to hint the correct and true Root Cause for a visible malfunction



3.  Losses

Limiting here ourselves to the special case of the Electronic Inspectors’ in the Packaging Lines, an example of total losses is the sum of:

  • false rejects (false positives);
  • production lost because of unadequately trained Operators;
  • production lost because of downtimes determined by the Inspectors.

This last point, itself a superposition of several other components, like the Electronic Inspector:

  (Click to enlarge)  Automation and Optoelectronic failures due to causes external to the hardware are strictly related to the constantly monitored respect of basic rules.  Rules inherent to the power line conditioning, grounding, immunity to environmental factors (i.e., humidity, temperature) and EMI

  • mechanical failures, e.g., conveyor belts in a linear EBI, levers into rejectors, gears, solenoid valves into rejectors, pneumatic cylinders, rejectors’ segments, etc.
  • optoelectronic failures, e.g., inspection glasses, flashers, cameras, electronic cards, their power suppliers, sensors, tracking photosensors, cables, connectors, etc.
  • automation failures, e.g., PLCs, their power suppliers, FlashPROMs, relays, contactors, magnetothermal switches, cables, connectors, cables toward solenoid valves, connectors of solenoid valves, etc.
  • software failures, e.g., watchdog, lengthy reboot mechanisms, slow manual-only operator reboot required, overflow, full buffer, etc.
  • parameterization inadequacies, e.g. unproperly set ranges of grey of an inspection program, unproperly set counter limits or ranges of an inspection program, non-optimal offset parameter, non-optimal gain parameter, non-optimal distance to trigger parameter, etc.

As an example, parameterization inadequacies are in the majority of the cases the visible effect of the Bottler's underestimation of the complexity of the Electronic Inspector.  

This, truer in case of systems equipped with cameras, where the real number of discrete variables to process for each one container inspected, each variable existing in a range of > 65535 values, can total several millions.  Advanced training for the Maintenance Dept. staff the only possible and economic solution.  Parameterization inadequacies also cause the majority of the false rejects of the Electronic Inspector.   What is surely true if the Electronic Inspector really was correctly commissioned by the staff proposed by the Vendor…   

  The hardware faults can cost a fortune, in terms of lost production and simultaneous expenses of a forcedly stopped Food and Beverage Packaging Line.  Also, we lived cases where hardware faults implied negative effects over the Maintenance Staff management.  A portion bigger than commonly expected of the hardware faults of sensors, electronic cards, human-machine interfaces, PLCs is Design-related.  But, the real problem of the Maintenance Dept. staff is to demonstrate.  To show with facts to the Vendor, the cause external to its ambient, practices and process, and internal to the devices and/or design and/or to the extremely frequent installation malpractices.  We can help you to terminate all this











In a complex Food and Beverage Machine, whatever its kind and purpose, the effects can be easily and frequently are confused with causes. The equivalent of a function, of another function, of another function:

           y  =  f( g( h( l( m( n( o( p( q( r( ….. ( x )…..)))))))))


where each of the functions is referred to random variables, and we’ll be still underestimating the complexity.  That’s the main reason for the difficulty to hint the correct and true Root Cause for a visible malfunction.  It is important to have a deep insight at least of the top ten performance killers.  This list can be generated when we analyze the causes of failure and the subsequent production losses.  There are different types of failure, so it is important to apply the proper tool to analyze the many potential root causes. 


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This website has no affiliation with, endorsement, sponsorship, or support of Heuft Systemtechnik GmbH, MingJia Packaging Inspection Tech Co., Pressco Technology Inc., miho Inspektionsysteme GmbH, Krones AG, KHS GmbH, Bbull Technology, Industrial Dynamics Co., FT System srl, Cognex Co., ICS Inex Inspection Systems, Mettler-Toledo Inc., Logics & Controls srl, Symplex Vision Systems GmbH, Teledyne Dalsa Inc., Microscan Systems Inc., Andor Technology plc, Newton Research Labs Inc., Basler AG, Datalogic SpA, Sidel AG, Matrox Electronics Systems Ltd.  


                                                                                                                                                                                                                                                                                                                                                                                                                                                         
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