FMEA Analysis: Example and Application

During the development and production of various equipment, defects periodically occur. What is the result? The manufacturer incurs significant losses associated with additional tests, checks and changes to the project. However, this is not an uncontrolled process. You can evaluate potential threats and vulnerabilities, as well as analyze potential defects that could interfere with the operation of the equipment, using the FMEA analysis.

This analysis method was first used in the USA in 1949. Then it was used exclusively in the military industry in the design of new weapons. However, already in the 70s, FMEA ideas came to the attention of large corporations. One of the first to implement this technology was Ford (at that time - the largest car manufacturer).

Nowadays, the FMEA analysis method is used by almost all engineering companies. The basic principles of risk management and failure analysis are described in GOST R 51901.12-2007.

Definition and essence of the method

FMEA stands for Failure Mode and Effect Analysis. This is a technology for analyzing the varieties and consequences of possible failures (defects due to which the object loses the ability to perform its functions). What is this method good for? It gives the company the opportunity to anticipate possible problems and malfunctions at the design stage. During the analysis, the manufacturer receives the following information:

• list of potential defects and malfunctions;
• analysis of the causes of their occurrence, severity and consequences;
• recommendations for risk reduction in order of priority;
• general assessment of the safety and reliability of products and the system as a whole.

The data obtained as a result of the analysis are documented. All detected and studied failures are classified according to the degree of criticality, ease of detection, maintainability and frequency of occurrence. The main task is to identify problems before they arise and begin to affect the company's customers.

Scope of FMEA analysis

This research method is actively used in almost all technical sectors, such as:

• car and shipbuilding;
• aviation and space industry;
• chemical and oil refining;
• construction;
• manufacturing of industrial equipment and machinery.

In recent years, this method of risk assessment has been increasingly used in the non-productive sphere, for example, in management and marketing.

FMEA can be carried out at all stages of the product life cycle. However, most often the analysis is performed at the stage of product development and modification, as well as when using existing structures in a new environment.

Kinds

Using FMEA technology, they study not only various mechanisms and devices, but also the processes of company management, production and operation of products. In each case, the method has its own specific features. The object of analysis may be:

• technical systems;
• constructions and products;
• processes of production, assembly, installation and maintenance of products.

When examining the mechanisms, they determine the risk of non-compliance with standards, malfunctions during operation, as well as breakdowns and a decrease in service life. This takes into account the properties of materials, the geometry of the structure, its characteristics, interaction interfaces with other systems.

FMEA analysis of the process reveals inconsistencies that affect product quality and safety. Customer satisfaction and environmental risks are also taken into account. Here problems can arise from the side of a person (in particular, employees of the enterprise), production technology, raw materials and equipment used, measuring systems, and environmental impacts.

When conducting research, different approaches are used:

• "from top to bottom" (from large systems to small parts and elements);
• "from bottom to top" (from individual products and their parts to the production system).

The choice depends on the purpose of the analysis. It can be part of a comprehensive study in addition to other methods, or used as a stand-alone tool.

Stages

Regardless of specific tasks, the FMEA analysis of the causes and consequences of failures is carried out according to a universal algorithm. Let us consider this process in more detail.

Expert group training

First of all, you need to decide who will conduct the study. Teamwork is one of the key principles of FMEA. Only such a format ensures the quality and objectivity of the examination, and also creates space for innovative ideas. As a rule, a team consists of 5-9 people. It includes:

• project Manager;
• process engineer performing process development;
• design engineer;
• representative of the production or quality control service ;
• Consumer Relations Officer

If necessary, qualified specialists from third-party organizations may be involved in the analysis of structures and processes. Discussion of possible problems and ways to solve them takes place in a series of meetings lasting up to 1.5 hours. They can be carried out both in full or in part (if the presence of certain experts is not necessary to resolve current issues).

Study project

To conduct an FMEA analysis, you need to clearly identify the object of study and its boundaries. If we are talking about the technological process, the initial and final events should be designated. For equipment and structures, everything is simpler - you can consider them as complex systems or focus on specific mechanisms and elements. Inconsistencies can be considered taking into account the needs of the consumer, the stage of the product life cycle, geography of use, etc.

At this stage, the members of the expert group should receive a detailed description of the object, its functions and principles of work. Explanations should be accessible and understandable to all team members. Usually, presentations are made at the first session, experts study the instructions for the manufacture and operation of structures, planned parameters, regulatory documents, and drawings.

# 3: List potential defects

After the theoretical part, the team proceeds to assess possible failures. A complete list of all possible inconsistencies and defects that may occur at the facility is compiled. They can be associated with the breakdown of individual elements or their improper functioning (insufficient power, inaccuracy, low productivity). When analyzing processes, it is necessary to list specific technological operations during which there is a risk of errors - for example, failure to perform or incorrect execution.

Description of causes and consequences

The next step is an in-depth analysis of such situations. The main task is to understand what can lead to the occurrence of certain errors, as well as how the detected defects can affect employees, consumers and the company as a whole.

To determine the probable causes of defects, the team studies the descriptions of operations, the approved requirements for their implementation, as well as statistical reports. In the protocol of the FMEA analysis, you can also specify risk factors that the company can adjust.

At the same time, the team is considering what can be done to eliminate the chance of defects, offering control methods and the optimal frequency of inspections.

Expert estimates

What's next? FMEA team members begin to analyze each failure according to three main criteria:

1. S - Severity. Determines how severe the consequences of this defect for the consumer will be. It is evaluated on a 10-point scale (1 - almost no effect, 10 - catastrophic, in which the manufacturer or supplier may incur criminal punishment).
2. O - Occurrence / Probability. It shows how often a certain violation occurs and whether the situation can happen again (1 - it is extremely unlikely, 10 - failure is observed in more than 10% of cases).
3. D - Detection / Detection. Parameter for evaluating control methods: will they help to timely identify inconsistencies (1 - almost guaranteed to detect, 10 - hidden defect that cannot be detected before the consequences).

Based on these assessments, the priority number of risks (FDI) for each type of failure is determined. This is a general indicator that allows you to find out which breakdowns and violations pose the greatest threat to the company and its customers. It is calculated by the formula:

The higher the PSR, the more dangerous the violation and the more damaging its consequences. First of all, it is necessary to eliminate or reduce the risk of defects and malfunctions in which this value exceeds 100-125. From 40 to 100 points, violations that have an average level of threat are scored, and an FHR of less than 40 indicates that the failure is insignificant, rarely occurs and can be detected without problems.

Development of proposals and recommendations

After evaluating the deviations and their consequences, the FMEA working group identifies priority areas of work. The primary task is to draw up a corrective action plan for the bottlenecks - elements and operations with the highest HR values. To reduce the threat level, it is necessary to influence one or several parameters:

• eliminate the initial cause of the failure by changing the design or process (grade O);
• prevent the occurrence of a defect using statistical regulation methods (score O);
• mitigate negative consequences for buyers and customers - for example, lower prices for defective products (grade S);
• Introduce new tools for the timely detection of faults and subsequent repairs (grade D).

So that the company can immediately begin to implement the recommendations, the FMEA team at the same time develops a plan for their implementation indicating the sequence and timing of each type of work. The same document contains information about the performers and those responsible for carrying out corrective actions, sources of financing.

Summarizing

The final stage is the preparation of a report for company executives. What sections should it contain?

1. Review and detailed notes on the progress of the study.
2. Potential causes of defects in the production / operation of equipment and technological operations.
3. The list of probable consequences for employees and consumers is separate for each violation.
4. Assessment of the level of risk (how dangerous are possible violations, which of them can lead to serious consequences).
5. A list of recommendations for maintenance services, designers and planners.
6. Schedule and reports on corrective actions based on the results of the analysis.
7. A list of potential threats and consequences that have been eliminated by changing the project.

All tables, graphs and diagrams are attached to the report, which serve to visualize information about the main problems. Also, the working group should provide the used schemes for assessing inconsistencies in terms of significance, frequency and probability of detection with a detailed breakdown of the scale (which means one or another number of points).

How to populate the FMEA protocol?

During the study, all data should be recorded in a special document. This is the FMEA Cause and Effect Analysis Protocol. It is a universal table where all information about probable defects is entered. This form is suitable for the study of any systems, objects and processes in any industries.

The first part is filled on the basis of personal observations of team members, study of enterprise statistics, work instructions and other documentation. The main task is to understand what can interfere with the mechanism or the performance of any task. At meetings, the working group must evaluate the consequences of these violations, answer how dangerous they are for workers and consumers, and what is the likelihood that a defect will be detected at the production stage.

The second part of the protocol describes the options for preventing and eliminating inconsistencies, a list of activities developed by the FMEA-team. A separate column is provided for the appointment of those responsible for the implementation of certain tasks, and after making adjustments to the design or organization of the business process, the head indicates in the protocol a list of work performed. The final step is to re-rate, taking into account all the changes. Comparing the initial and final indicators, we can conclude about the effectiveness of the chosen strategy.

A separate protocol is created for each object. At the very top is the title of the document - "Analysis of the types and consequences of potential defects." The equipment model or the name of the process, the dates of the previous and next (scheduled) inspections, the current date, as well as the signatures of all participants in the working group and its leader are indicated a little lower.

An example of an FMEA analysis (Tulin Instrument-Making Plant)

Consider how the process of assessing potential risks on the experience of a large Russian industrial company. At one time, the leadership of the Tulin Instrument-Making Plant (TVES OJSC) was faced with the problem of calibrating electronic scales. The company produced a large percentage of malfunctioning equipment, which the technical control department was forced to send back.

After examining the sequence of steps and the requirements for the calibration procedure, the FMEA team identified four subprocesses that most affected the quality and accuracy of the calibration.

• moving and installing the device on the table;
• checking the position by level (the balance should be located 100% horizontally);
• arrangement of goods in the reference points of the platform;
• registration of frequency signals.

What types of failures and malfunctions were recorded during these operations? The working group identified the main risks, analyzed the causes of their occurrence and possible consequences. Based on expert evaluations, the HRI indicators were calculated, which made it possible to identify the main problems - the lack of clear control over the performance of work and the condition of equipment (bench, weights).

To eliminate risk factors, recommendations were developed for additional training for employees, modification of the bench top and the purchase of a special roller container for transporting weights. The purchase of an uninterruptible power supply unit solved the data loss problem. And in order to prevent problems with calibration in the future, the working group proposed new maintenance schedules and planned calibration of weights - checks began to be carried out more often, due to which damage and malfunctions can be detected much earlier.