In order for sustainable business success to be possible at all, products and processes that meet the increasing demands of customers and standards are required. To ensure this, products and processes must be planned with foresight. In this context, it is particularly important to identify and evaluate risks at an early stage in order to avoid errors in advance. In quality management, one method contributes to this in particular – the Failure Mode and Effect Analysis, FMEA for short.
Do you know all the factors that influence the success of your company? Well, at least some are widely known: faulty processes, poor product quality and a lack of proactivity ensure that companies cannot survive in the long term in a constantly growing market. This is also evident from the fact that customers today can obtain information about the quality of the product of their choice in advance and digitally. Companies whose products are judged to be defective have a decisive disadvantage as a result. FMEA can help to prevent this from happening in the first place: it systematically looks for possible risks in product design and the production process. To minimize identified risks, effective preventive measures are developed and introduced – with the aim of avoiding errors before they occur.
FMEA is a generally applicable, analytical method in quality management, a component of the Automotive Core Tools and has become a proven instrument in the everyday life of many companies. FMEA is used especially during the development of new products or before the introduction of new technologies in the product manufacturing process. Potential errors and their consequences for customers as well as the possible causes are systematically identified and described. Furthermore, they are evaluated according to predefined criteria. Companies can effectively counter the risks uncovered in this way because suitable actions for avoiding errors are established at an early stage. Successfully performed FMEAs make a significant contribution within the company so that only fault-free products find their way to the customer.
The main objective of FMEA is therefore to avoid errors instead of correcting errors. It is generally known that corrections are often more costly than precautions. And the later in the manufacturing process mistakes are recognized and corrections have to be made, the more cost-intensive the necessary actions become. The detection of weaknesses and risks in the planning process avoids consequential costs in production and averts damage to the customer. When carrying out FMEAs, one deals intensively with risks – with the question of how to reduce them and what can be improved. In this way, the risk awareness required by ISO 9001 is sharpened among all those involved. In addition, findings from FMEAs serve as a useful store of knowledge for the development of future products.
Not so long ago, there were described methods for FMEA, which were used especially in the automotive industry. However, different approaches were followed, including which criteria should be used for risk assessment and how the results of an FMEA should be presented for communication with customers. This often resulted in additional work, depending on the manufacturer for which products or components are manufactured. For this reason, the two FMEA guidelines according to AIAG (Automotive Industry Action Group) and VDA (Verband der Automobilindustrie) were harmonized, so that there is now a new, uniform standard. The focus of the new FMEA guideline is now on a systematic procedure in seven steps and on uniform criteria for risk assessment. The significance of possible failure consequences and the probability that a failure (or cause) will occur and that it will be detected in time are evaluated. On this basis, for all identified risks, the “action priority” is used to determine how urgently action is needed to reduce the risk. This enables companies to focus on the really important measures that ultimately serve to protect customers from defective products.
A basic distinction is made between two types of FMEA: Design FMEA and Process FMEA. Other, more common variants are derived from these two types. But how does one proceed with an FMEA? The seven steps are briefly described below.
Planning and Preparation: First of all, the FMEA must be planned and prepared; this step involves defining the goal, the team, the milestones, the basis for evaluation, the interfaces, the methodology used, the scope, the depth of consideration and other definitions.
Structure Analysis: The structural analysis is an opportunity to keep the overview of the FMEA. In it the scopes, which were defined in the first step, are visualized and thus depicted clearly.
Function Analysis: Within the FMEA, the functional analysis creates understanding for the product or process. It is created parallel to the structural analysis and provides for the derivation of functions of the system or process from requirements, empirical values or the specifications.
Failure Analysis: In this step of the FMEA, possible failures are systematically derived from the performed functional analysis and linked together on the basis of the structure. As a result, failure networks are created from which the consequences and causes of a failure are identified. In this step it is important to evaluate the consequences of the error in terms of its significance for the customer or for subsequent process steps.
Risk Analysis: In the risk analysis, the existing or planned actions are first described. On this basis, the probability of occurrence (A) and detection (E) for the failure or cause is evaluated. This and the significance (B) of the consequences are used to determine the action priority (high, medium, low). This is the starting point for product or process optimization – the action priority (AP) replaces the previous risk priority number (RPN).
Optimization: according to the previously determined action priority, new measures (avoidance, detection) are jointly developed to achieve risk reduction. Taking the new measures into account, the risk is reassessed. This process is repeated until all risks have reached an acceptable level.
Documentation of Results: In addition to the documentation, which usually takes place in a form, and the communication of the compiled results including the technical risks, the last step of the FMEA also includes the examination whether the newly introduced actions are effective and whether the predicted risk reduction could be achieved.