Zeroing In On Failure Mode

Saturday, September 16th, 2017

Consumer confidence and the food industry’s reputation have been severely shaken by the recent series of food safety incidents. Integrating the failure mode and effect analysis method into the hazard analysis critical control point system can provide food manufacturers a much clearer picture and assist them in controlling the vital areas along the supply chain. By Wang Xiaochuan and Lu Qiang, China University of Mining and Technology

AgriLife Today 

Offering rich nutrition and a delicious taste, meat products are one of man’s most important and favourite food. Meat safety is a global problem, but it is prominent particularly in China, where it is hard to prohibit inferior and/ or diseased meat.

As a result, the country has experienced frequent outbreaks of avian influenza, aphtha and animal epidemics. In addition, there are also various food safety incidents pertaining to the use of food additives, which have sounded the alarm bell on the quality of meat products for consumers.

There is a need for the country to continue to establish and perfect a safety supervision and management system for meat products, and to prevent and control each link in the supply chain with advanced modern quality management principles and quality control technologies.

Hazard analysis critical control point (HACCP) is a kind of systematic method used to identify, evaluate and control the whole food chain. The formulation and implementation of a meat product HACCP plan based on failure modes and effective analysis (FMEA) can promote scientific and effective operation of a safety supervision and management system that will essentially improve the safety of meat products.

The HACCP system is a preventive system that controls food safety hazards based on effective implementation of good manufacturing practice (GMP) and sanitation standard operation procedure (SSOP). Its purpose is to determine the possible hazards in any link of the food chain and take preventive measures.

The general steps for the implementation of a HACCP plan are as follows:

  • Carry out a hazard analysis, list all possible hazards and put forward preventive and control measures
  • Determine the critical control points
  • Establish the critical limit according to each critical control point
  • Monitor all the critical control points
  • Establish the corrective actives when the monitoring shows that a critical control point is out of control
  • Set up a verification procedure for the effective operation of HACCP
  • Establish the above steps and ensure proper record keeping

FMEA Principles

US Department of Agriculture

FMEA is a basic tool in the field of reliability engineering and through the identification of each potential failure mode, it can confirm and analyse the influences and consequences of the failure, find out the mechanism of production and the fundamental cause of the failure mode, and then sort out the weak link of the system and formulate improvement and control measures.

First of all, FMEA can identify the potential failure modes in the design and process control of products or the system on the basis of the existing information, analyse the influences and find out the failure causes and mechanism.

Through statistical methods, it will determine severity (S), occurrence (O), and detection (D) of the failure. Using the formula risk priority number (RPN) = S x O x D, it will identify the degree of influence of the failure modes and enhance the reliability of the products or systems by formulating improvement and optimisation measures.

Among them S is the degree of influence on the system, next step, product or customers when the potential failure mode happens. Usually, it only applies to the consequences of failures and is generally divided into different levels using a scale of 1 to 10.

O is the possibility of frequency of the cause or mechanism of failure and is generally scored from 1 to 10. D refers to the non-detectable degree of influence or nondetection of the cause or mechanism that causes a failure mode and is also ranked from 1 to10.

The FMEA analysis of meat products should follow the basic principles of the FMEA design, combine the characteristics of meat products, and design FMEA forms of the meat products, which will mainly include functional requirements of the meat products, potential function failure modes, consequences of potential failures, causes and mechanisms of potential failures, risk priority numbers, improvement measures and other elements.

The potential failure modes of meat products refer to the products’ existing and potential problems or deviations in food quality and safety. Due to meat products’ characteristics of particularity, inseparability and non-reworkable functions, a comprehensive analysis on the whole flow of the supply chain on main influence factors such as personnel, machinery, materials, methods and environment should be conducted, and a list of potential failure modes should be created.

Analysis Of Failure Causes

The fault tree analysis method should be used to analyse faulty meat products, for which the main potential failure modes include contamination of meat sources, cross contamination, contamination of packing materials, lack of cold storage protection and false labelling.

The occurrence of any kind of potential failure mode will affect the quality of meat products and customer satisfaction, and reduce the safety level of the products.

Consequences of potential failures are that caused by the occurrence of meat products’ potential failure modes in the entire supply chain. For example, the consequence of false labelling is that expired meat products may be sold and consumers may suffer severe health consequences.

Causes and mechanisms of potential failures refer to the reasons for the failure modes of meat products. There may be many different causes of a failure mode. For example, reasons for cross contamination include unsterilized processing or splitting tools, or cross contamination from operators.

The meat product HACCP plan, formulated based on HACCP principles and in accordance with the aforementioned general implementation steps, is a document used to ensure that the hazards of all links of the supply chain with great significance to the meat products can be controlled.

Plan Formulation Process

Jonny Hunter, Madison, US

The general flow of the supply chain of meat products follows cultivation, slaughtering, processing, storage, distribution and transportation, and finally to sales.

With the results from the meat product FMEA, the meat products’ potential failure modes with higher RPN values or better ranks should be determined, the meat products’ flow of supply chain studied, and the relationship between these failure modes and each link of the supply chain analysed so as to determine the critical control points (CCPs).

Generally, the potential failure modes with higher RPN values for meat products are contamination of meat sources and lack of cold storage protection. The main links of the supply chain where failures occur will be determined as CCP.

The CCP of the supply chain of meat products are hence cultivation, distribution and transportation, and sales.

Therefore, the formulation and implementation of a meat product HACCP plan based on FMEA principles should include the following five main steps:

  • Develop CCP monitoring procedures. Determine the significant hazards of the meat product supply chain CCP and set up the critical limits according to the principle of hazard control and critical limit determination.
  • Work out the monitoring content of all critical limits, how to monitor them, when to monitor them and who to monitor them.
  • Establish corrective measures. When the monitoring shows that the CCPs deviate or do not conform to the critical limits, rectify the deviation and carry out correction and isolation to ensure that there is effective control over the CCPS in the flow of the meat product supply chain.
  • Set up verification procedures. These procedures are used to verify the effectiveness of the formulation and implementation of the meat product HACCP plan and to promote the continuous improvement of the system.
  • Establish a documentation and record keeping system. The system can be evidence of effective operation of the meat product HACCP system and can provide input information for assessment of the operational effects of the safety quality management system.

The application of FMEA can provide a comprehensive analysis of the potential failure modes of meat products. The risk priority numbers of the failures provide a basis for the identification of the CCPs throughout the supply chain and together with the supervision and control of the HACCP principles, they can be used to formulate a meat product HACCP plan.

The formulation and implementation of a meat product HACCP plan based on FMEA is beneficial to the improvement of the safety of meat products and the promotion of sustainable and healthy development of the meat industry. At the same time, it provides a method, basis and reference for other food safety issues.