Method for computer-aided analysis of the reliability of a technical system, corresponding device, and a corresponding technical system

• US 8,131,505 B2
• Filed: 09/04/2006
• Issued: 03/06/2012
• Est. Priority Date: 09/30/2005
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Ehlers, Petra, Klein, Wolfram, Sutor, Ariane
• Primary Examiner(s): Huynh, Phuong
• Application Number:
  US11/992,711
• Publication Number:
  US 20090222239A1
• Time in Patent Office: 2,010 Days
• Field of Search: 702182-189, 702/191, 702121-123
• US Class Current: 702/182
• CPC Class Codes: G05B 23/0251 Abstraction hierarchy, e.g. "complex systems", i.e. system is divided in subsystems, subsystems are monitored and results are combined to decide on status of whole system

Abstract

The invention relates to a method for the computer-assisted analysis of the reliability of a technical system comprising a plurality of technical components. According to the method, the reliabilities of the components are respectively described by a component function that depends on at least one parameter and a parameter interval of the at least one parameter, which is associated with the components and influences the reliability of the components; a system reliability of the technical system is determined from the reliabilities of the components; a variation value is respectively determined for at least some of the components f&, constituting a value for the variation of the system reliability according to the variation of the parameter interval of the respective component; and an influence quantity relating to the influence of the respective components on the system reliability is respectively determined for at least some of the components from the variation value.

Claims

1. A method for computer-aided analysis of a reliability of a technical system with a plurality of technical components, comprising:

describing the reliability of each of the plurality of technical components by a component function ƒ

for each component under consideration of the plurality of technical components, wherein the component function is described by a distribution function comprising parameter t representing an operating time of the technical system, parameter t₀ representing a maintenance interval for the technical component under consideration, and parameter λ

representing a parameter that describes the reliability of the component under consideration and wherein the distribution function comprises an exponential function represented as ƒ

(t, t₀)=1−

e<sup>−

λ

(tmodt0)</sup> wherein tmodt₀ represents a modulo function;

determining a system reliability for the technical system in accordance with a system reliability function F comprising a mathematical combination of the reliabilities of the components;

determining for each of at least some of the components a change magnitude which is a measure of the change in the system reliability as a function of the change in the maintenance interval for the component under consideration; and

determining, using a computer, a factor for the effect of the component concerned on the system reliability via the change magnitude for each of at least some of the components,

wherein, based on the factors determined, at least one component is identified having a greater effect on the system reliability than the other.

2. The method as claimed in claim 1, wherein the maintenance interval for a component under consideration differs from maintenance intervals for other components.

3. The method as claimed in claim 1, wherein the reliabilities of the components are variables which characterize the probability of a fault and/or failure and/or the availability of the component concerned.

4. The method as claimed in claim 1, wherein the component functions comprise at least one probability distribution function.

5. The method as claimed in claim 4, wherein the probability distribution function is selected from the group consisting of:

a Weibull distribution, a gamma distribution, a lognormal distribution, an exponential distribution and combinations thereof.

6. The method as claimed in claim 1, wherein the mathematical combination of the reliabilities of the components comprises using a Boolean algebra.

7. The method as claimed in claim 1, wherein each of the change magnitudes comprises the derivative of the system reliability with respect to the maintenance interval concerned.

8. The method as claimed in claim 1, wherein the factors for a plurality of the components comprise in each case an integral, with respect to the maintenance interval of the change magnitude for the component concerned.

9. The method as claimed in claim 1, wherein the factors for each of the plurality of the components comprise the maximum value of the absolute value of the change magnitude for the component concerned in an interval of the operating time of the technical system.

10. The method as claimed in claim 1, wherein the factors for each of the plurality of the components comprise the absolute value of the change magnitude for the component concerned at a predefined value of the operating time of the technical system.

11. The method as claimed in claim 1, wherein the reliability of a power station, and/or of a technical control system is analyzed.