DE102006057702A1 - Method for failure mode and effect analysis of system, involves integrating operator of system as system element and errors caused by driver are identified with high risk priority number - Google Patents

Abstract

The method involves integrating operator of a system as the system element. The operator is integrated in the structural tree in the failure network. The errors caused are attributed to the driver, and are evaluated with the assigned errors or consequences of errors filled in the form on the basis of the comparison. Errors caused by the driver are identified with a high risk priority number and specific timely preventive measures are taken.

Description

The The present invention relates to a method for error possibility and influence analysis (FMEA) according to the generic term of claim 1

The Failure Mode and Influence Analysis (FMEA) is a well-known and worldwide in many Industries Method, functional relationships (including error behavior) to describe, evaluate, measures to define and monitor their execution. Here are usually the system components and the system structure, as a rule of a structure tree, i. the system will be in his Components decomposed, followed by the functions of the components be determined; according to the state of the art, the function a subcomponent is a subfunction of the respective superordinate component represents.

Of Further, according to the prior art, each function of a Component assigned to corresponding malfunctions (fault network), which may be the component describe occurring errors, the error sequences in the respective parent Component are set as malfunction. From the prior art is known, the possible To enter errors of a system in a form, which the connections between Structure elements, functions, error networks and measures (Avoidance and detection measures) represents.

• 1. Wahrscheinlichkeit A des Auftretens eines Fehlers (unwahrscheinlich = 1, sehr gering = 2–3, gering = 4–6, mäßig = 7–8, hoch = 9–10);
• 2. Bedeutung B des Fehlers = Auswirkung auf den Kunden (kaum wahrnehmbar = 1, unbedeutend bzw. geringe Belästigung = 2–3, mäßig schwer = 4–6, schwere Auswirkung, Verärgerung = 7–8, äußerst schwere Auswirkung = 9–10) und
• 3. Wahrscheinlichkeit E der Entdeckung des Fehlers (hoch = 1, mäßig = 2–5, gering = 6–8, sehr gering = 9, unwahrscheinlich = 10).

As part of a Failure Mode and Effects Analysis (FMEA), such as in the EP 1 192 543 B1 described the following questions and evaluated as follows:

• 1. Probability A of the occurrence of an error (unlikely = 1, very low = 2-3, low = 4-6, moderate = 7-8, high = 9-10);
• 2. Meaning B of the defect = impact on the customer (barely noticeable = 1, insignificant or slight annoyance = 2-3, moderately severe = 4-6, severe impact, annoyance = 7-8, extremely severe impact = 9-10 ) and
• 3. Probability E of finding the error (high = 1, moderate = 2-5, low = 6-8, very low = 9, unlikely = 10).

By Multiplication of the factors A, B and E becomes a risk priority number RPZ = A × B × E for fixing the priority of a problem, where a value 125 is a medium priority and a value greater than 1000 a high priority means. The corresponding form usually contains the errors that Cause for this and the individual factors A, B, E and the errors associated Risk priority numbers RPN.

Lots Error or damage a system, in particular in the automotive industry (eg at a Manual gearbox), which also leads to error sequences in the parent System (eg vehicle) are caused by the driver. When studying systems with a method of error-prone and Influence Analysis (FMEA) it is not yet known to the operator of the systems, d. H. For the case of a vehicle the driver, in the FMEA methodology directly involve.

Of the present invention is based on the object, starting from known prior art, a method for error-possibility and influence analysis (FMEA), in the context of which the operator of the system under study in the analysis becomes.

These The object is solved by the features of claim 1. Further Embodiments of the invention and advantages are apparent from the dependent claims.

Therefore is in the context of the method according to the invention to the error possibility and Influence Analysis (FMEA) suggested that the operator of the Systems is integrated as a system element in the process.

Especially the operator is placed in the structure tree, the error network and in the form for implementation integrated into the process.

According to the invention the drivers assigned to the driver are assigned with the assigned error causes Errors or error sequences in the forms subjected to a rating. Based on this review can Driver causes associated with a high risk priority number recognized and timely avoidance measures be determined.

By the concept of the invention is advantageously an early one Recognizing interactions between driver and system allows; In particular, it detects which operating errors and which risks to lead.

Of others can early Measures set which reduce or prevent the occurrence of incorrect operation. This also results in the advantage that field damage and so that complaint costs are reduced.

The The invention will be explained in more detail below with reference to the accompanying figures by way of example.

It demonstrate:

1 a structure tree modified according to the invention for carrying out a method for error possibility and influence analysis (FMEA);

2 a modified according to the invention error network for performing a method for error possibility and influence analysis (FMEA) and

3 a modified according to the invention form for performing a method for error possibility and influence analysis (FMEA).

According to the invention, it is proposed to integrate the operator of the system as a so-called system element in the structure tree of the method. This is based on 1 illustrated; in the example shown the error "drive train while driving interrupted" several possibilities of incorrect operation by the driver are specified.

The operator of the system according to the invention is also integrated into the error network. This is the subject of 2 ; in the example shown, the error "drive train while driving interrupted" as an additional cause of failure, the actuation of the clutch by the driver or due to the driver is not fully open clutch specified.

The integration of the operator as a system element in the process also takes place in the form used, as shown 3 illustrated. Here, for the error "powertrain while driving interrupted" caused by the driver's operation, as a new avoidance measure, it is proposed to reduce the clutch opening point to 50% of the pedal travel, thereby judging the occurrence probability by a factor of 2, instead of Factor 5, which indicates the probability of the error occurring in the event that the clutch opening point is at 80% of the pedal travel.

By the procedure according to the invention In the given example, the risk priority number RPZ becomes more advantageous Way reduced from 225 to 90, which is the main advantage of here presented method, namely the reduction of frequency of occurrence an error operation clarifies.

Claims (3)

Method for error possibility and influence analysis (FMEA) of a system, characterized in that the operator of the system is integrated as a system element in the process. Method for error possibility and influence analysis (FMEA) of a system according to claim 1, characterized in that the server into the structure tree, the error net and the form to execution of the procedure is integrated. Method for error possibility and influence analysis (FMEA) of a system according to claim 1 or 2, characterized in that that the causes of the fault assigned to the driver with the associated Errors or error sequences in the forms subjected to a rating based on this rating, causes of failure associated with the driver detected with a high risk priority number and avoidance measures be determined.