1. One of the tools used better than HACCP in managing food safety is “Risk Assessment”. Risk
assessment include : disease characterization, dose-response assessment, exposure assessment,
and risk characterization. Quantitative data is critical for risk assessment to realize its full value,
yet much of our knowledge about the incidence of pathogens or toxins in foods, dose-response
knowledge, incidence of acute food-borne illness, incidence of chronic sequelae, and cost of
food-borne illness is qualitative or estimates are controversial. Predlctlve modelling should help
to improve estimates and thereby allow yuantltatlon of food safety risks (Foegeding, P. M. ,
1997).
FMEA is a popular and practical quality and risk assessment tool. It is useful to define, identify,
and eliminate known and/or potential failures, problems, errors from a system, design, process,
and/or service (Stamatis 2003). A failure mode is defined as the manner in which a component,
subsystem, system, or process can potentially fail to meet the designed intent (Liu, J. et al. ,
2010). A successful FMEA implementation helps the manufacturing team to identify potential
failure modes based on their past experience with similar products or processes; hence enabling
the team to eliminate or reduce system failures with the minimum effort and resource
expenditure. From the literature, the use of FMEA in the food industry is not new. Scipioni et al.,
2002 and Scipioni et al., 2005 demonstrated an FMEA which was integrated with the hazard
analysis and critical control points approach in a food company. It was used as a tool to assure
product quality and as a means to improve the operational performance of the production cycle.
Besides, FMEA was employed as a risk assessment tool in salmon manufacturing
(Arvanitoyannis and Varzakas, 2008) and red pepper spice production processes (Jong, C. H. et
al. , 2013).
Recently, a number of enhancements to FMEA using soft computing modeling techniques have
been proposed, e.g., the use of a Fuzzy Inference System (FIS) to replace the conventional Risk
Priority Number (RPN) model in FMEA (Liu et al., 2010, Yang et al., 2008, Guimares and Lapa,
2004 and Tay and Lim, 2006). The conventional RPN score is obtained by multiplying three risk
factors, i.e., Severity (S), Occurrence (O), and Detect (D), RPN = S × O × D ). As an
alternative, the FIS-based RPN model uses an FIS model to aggregate these three risk factors,
and produces a fuzzy RPN (FRPN) score, i.e.,FRPN=fRPN(S,O,D). The FIS-based RPN model
has been successfully applied to a variety of domains, e.g. maritime ( Yang et al., 2008), nuclear
power plant ( Guimares and Lapa, 2004), and semiconductor manufacturing ( Tay and Lim,
2006). The FIS-based model has several advantages. These include (i) the FIS-based model
allows the modeling of nonlinear relationships between the RPN score and the three risk factors
( Bowles and Peláez, 1995); (ii) it is robust against uncertainty and vagueness ( Yang et al.,
2008); and (iii) the scales of the attribute(s) can be qualitative, instead of quantitative ( Bowles
and Peláez, 1995).
2. The Process
Define the system to be analyzed, and obtain necessary drawings, charts, descriptions,
diagrams, component lists. Know exactly what you’re analyzing; is it an area, activity,
equipment? –all of it,or part of it?What targets are to be considered?Whatmissionphasesare
included?
Breakthe systemdownintoconvenientandlogical elements. System breakdown can be either
Functional (according to what the System elements “do”), or Geographic/Architectural (i.e.,
accordingto where the systemelements“are”),orboth(i.e.,Functional within the Geographic,
or vice versa).
Establish a coding system to identify system elements.
Analyze (FMEA) the elements.
Questions
1. Will a failure of the system result in intolerable/undesirable loss? If NO, document and end the
analysis. If YES, see (1.a.).
1.a.Divide the systemintoitssubsystems*.Askthisquestionsfor each subsystem: Will a failure
of thissubsystemresult in intolerable/undesirable loss? If NO, document and end the analysis. If YES,
see (1.b).
1.b. Divide eachsubsystemintoitsassemblies.Askthisquestionforeachassembly:Will afailure
of this assembly result in intolerable/undesirable loss? If NO, document and end the analysis. If YES,
continues this questioning through the subassembly level, and onward – into the piece-part level if
necessary.
2. For each analyzed element, what are the Failure Modes ?
3. For each failure mode, what are the Failure Effects ? FMEA – General FMECA – Severity and
Probability assessments
An example FMEA is given below.
3.
4. A case study of FMEA for Almond processing is as follows.
FMEA analysisInFMEA analysis,riskof contaminationanditspresence atHazardousFractioninthe final
product, is expressed with the Risk Priority Number (RPN) which is defined as follows:
RPN=S×O×D
Where
S: Severityof contaminationrisk,O:Occurrence of contaminatedingredient,D:Detection probability of
contaminated ingredient.
Corrective actioniscarriedout when RPN is greater than 130. The classification of hazardous elements
occurs according to the RPN assessment as can be seen in Table 1 and corrective actions are proposed
per identified hazard. Following calculation of the new RPN (the RPN after undertaking corrective
actions), a new classification of Hazardous Elements is shown in Table 1.
