JP2010102461A - Failure risk evaluation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve efficient equipment exchange when the failure of a plurality of pieces of equipment configuring a system is detected. <P>SOLUTION: A repair time/redundance presence and absence database (DB)(20) stores the repair time and the presence/absence of redundancy of each piece of evaluation target equipment. An equipment information collection device (22) collects the information of the transmission/reception traffic quantity of the equipment information of each piece of equipment. A loss quantity estimation device (26) calculates the time average of the transmission/reception traffic quantity about each piece of equipment, and calculates traffic quantity C<SB>data</SB>which is lost in detecting the repair time and the presence/absence of redundancy of the repair time/redundancy presence and absence DB (20) as loss quantity. A failure risk calculation device (32) multiplies the estimated failure risk by the failure rate/fault generation rate of a failure rate/fault generation rate DB(30), and stores the result as a failure risk in a failure risk DB(34). A display processing apparatus (36) displays the data of the DB(34) at a display device (40) according to the operation of an input device (38) by an operator. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a failure risk evaluation apparatus that evaluates the failure risk of individual network devices in operation.

  The conventional method for estimating the failure occurrence rate is to optimize the function parameters by presuming the function form of the life distribution in advance and obtaining the life of each of the n samples by an accelerated test. Non-patent document 1).

  There is also known a method for estimating the failure rate of equipment constituting the operating plant equipment based on design data for each equipment constituting the plant and inspection data after the start of operation (Patent Document 1).

  Patent Document 2 adds the expected value of loss at the time of an accident and the expected value of loss at the time of plant stop for the plant, and calculates the cost required for one or more maintenance methods. A method for selecting a minimum maintenance method that is equal to or less than the sum of expected values and a support device therefor are described.

Patent Document 3 describes that regarding the plant equipment, the frequency of occurrence of an accident and the degree of influence due to the occurrence of the accident are set, and the product of the frequency of occurrence of the accident and the degree of influence is evaluated as a risk.
JP 2004-191359 A JP-A-8-77211 JP 2002-123314 A Shin Makabe et al. "Statistical analysis of reliability model" Kyoritsu Shuppan 1989

  With the method described in Non-Patent Document 1, the failure rate of a device can be estimated, but since the loss due to the occurrence of a failure is unknown, the failure risk (expected value of loss caused by the failure) cannot be evaluated.

  The methods described in Patent Documents 1 to 3 can be applied to facilities in which the amount of loss (such as the amount of economic loss and the amount of social loss) in the event of an accident such as a nuclear power plant does not vary with time. Is. In network devices, the number of subordinate users and the amount of traffic change from moment to moment, and accordingly, the amount of loss when a failure occurs also varies with time. Even if the methods described in Patent Documents 1 to 3 are applied to such a device, the failure risk cannot be appropriately evaluated.

  Moreover, although the method of patent documents 1-3 can calculate the failure risk of an isolated facility like a nuclear power plant, a system in which a plurality of devices are connected to each other and influence each other like a network device. It is not suitable for calculating failure risk for each device individually.

  Therefore, the present invention provides a system in which individual devices are connected to each other and affect each other, and the amount of loss at the time of failure fluctuates with time, such as a communication network. It aims at presenting the failure risk evaluation apparatus which evaluates the failure risk of an apparatus.

  The failure risk evaluation apparatus according to the present invention includes a repair time / redundancy presence / absence database in which repair time and redundancy of each device are recorded for a plurality of devices constituting the system, and a failure rate of each device for the plurality of devices. And the failure rate / failure rate database in which the failure rate is recorded, the loss amount estimation means for calculating the loss amount when the device fails, and the loss rate by referring to the failure rate / failure rate database. The failure risk calculation means for calculating the expected loss at the time of failure of the equipment as the failure risk from the loss amount of each equipment estimated by the estimation means, and the failure risk of each equipment calculated by the failure risk calculation means. A failure risk database to be recorded, and display means for displaying the contents of the failure risk database are provided.

  According to the present invention, with regard to a plurality of devices constituting the system, the expected loss value in the case of failure of each device is lost considering the repair time and redundancy of each device and the failure rate / failure occurrence rate of each device. Since it is quantitatively evaluated as a risk, efficient equipment replacement becomes possible. Specifically, the loss due to equipment failure can be reduced as a whole by exchanging equipment in order from the equipment with the highest risk of failure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic block diagram of an embodiment of the present invention. A failure risk evaluation apparatus 10 shown in FIG. 1 is used by being connected to a network system as shown in FIG. 2, and evaluates the loss risk of each network device according to the amount of traffic that changes every moment. Specifically, the failure risk evaluation apparatus 10 is connected to a network 12, and a plurality of network devices 14-1 to 14-n are connected to the network 12. Then, the product of the failure rate (probability of failure within a unit time from the present time) or failure occurrence rate (probability of failure within the period T from the current time) and the loss amount when a failure occurs, for each device, The loss risk of the network devices 14-1 to 14-n is evaluated.

  The configuration and function of the failure risk evaluation apparatus 10 will be described with reference to FIG. The failure risk evaluation apparatus 10 includes a repair time / redundancy presence / absence database (hereinafter, database is abbreviated as DB) 20 as basic data for evaluation. FIG. 3 shows a structure and data example of the repair time / redundancy presence / absence DB 20. The repair time / redundancy presence / absence DB 20 includes a device ID field 20a, a repair time field 20b, and a redundancy presence / absence field 20c, and records the repair time and the presence / absence of redundancy for each network device 14-1 to 14-n to be evaluated. Is done. That is, identification information (ID) that identifies each network device 14-1 to 14-n is recorded in the device ID field 20a. In the repair time field 20b, a time required for repair when the device fails is recorded. In the redundancy presence / absence field 20c, flag information indicating whether or not the device is made redundant is recorded. This flag information is “0” when redundancy is provided, and is “1” when redundancy is not provided.

  The device information collection device 22 is connected to the network 12 via the network interface 24, and device information of the network devices 14-1 to 14-n, specifically, transmission / reception traffic of the network devices 14-1 to 14-n. Information on the amount (reception traffic amount InOctet and transmission traffic amount OutOctet) is collected. In the case of a general network device, this traffic volume information is included in the MIB information.

ここで、Ｍは、当該ネットワーク機器の下位ポート数を表す。また、「冗長の有無」の項は、冗長が有るときには０を、冗長が無いときには１をそれぞれ代入する。なぜならば、機器冗長が有る場合、当該ネットワーク機器が故障してもトラフィックが失われないので、損失量Ｃ_ｄａｔａを０とする。 For each network device, the loss amount estimation device 26 calculates the average value of the transmission / reception traffic volume of each lower port per hour, calculates the sum of the transmission / reception amounts of all the lower ports, and calculates the time average (eg, “ 1 month cumulative value / 720 hours "). In this embodiment, the time average of the amount of transmitted and received traffic is used as a guideline for quantitatively evaluating the loss. Next, the loss amount estimation device 26 refers to the repair time / redundancy presence / absence DB 20, and calculates the traffic amount C _data lost when each of the network devices 14-1 to 14-n fails as a loss amount. That is,

Here, M represents the number of lower ports of the network device. In addition, in the item “presence / absence of redundancy”, 0 is substituted when there is redundancy, and 1 is substituted when there is no redundancy. This is because if there is device redundancy, traffic is not lost even if the network device fails, so the loss amount C _{data is set} to zero.

The loss amount estimation device 26 stores the estimated loss amount in the loss amount DB 28 at the time of failure. FIG. 4 shows the structure and data example of the loss amount DB 28 at the time of failure. The loss amount DB 28 at the time of failure includes a device ID field 28a and a loss amount field 28b, and each network device 14-1 to 14-n has a loss amount at the time of failure occurrence (here, traffic amount C _data lost due to failure) ). Similar to the device ID field 20a of the repair time / redundancy presence / absence DB 20, identification information (ID) identifying each network device 14-1 to 14-n is recorded in the device ID field 28a. The loss amount field 28b stores a loss amount (traffic amount C _data ) when the network device fails.

  The failure rate / failure occurrence rate DB 30 holds information on failure rates and failure occurrence probabilities of the network devices 14-1 to 14-n. FIG. 5 shows the structure and data example of the failure rate / failure rate DB 30. The failure rate / failure occurrence rate DB 30 includes a device ID field 30a, a failure rate field 30b, a failure occurrence rate field 30c after 1 month, a failure occurrence rate field 30d after 2 months, and a failure occurrence rate after 3 months. The field 30e is provided, and holds a failure rate for each of the network devices 14-1 to 14-n and a plurality of failure occurrence rates on the time axis. The failure rate / failure rate DB 30 includes a database of failure rates and failure rates for each device that may be used as each network device 14-1 to 14-n, and each network device 14-1 that is actually used. It may be a database linked with ˜14-n type information.

  The failure risk calculation device 32 calculates the failure risk of each network device 14-1 to 14-n as an expected value of loss caused by the failure from the failure loss DB 28 and the failure rate / failure occurrence rate DB 30. Specifically, for each of the network devices 14-1 to 14-n, the loss amount (the value of the loss amount field 28b of the failure loss amount DB 28) and the failure rate (the failure rate field 30b of the failure rate / failure occurrence rate DB 30). And the product of the amount of loss and the failure occurrence rate for each period (values of occurrence probability fields 30c, 30d, and 30e of the failure rate / failure occurrence rate DB 30). When the change in failure occurrence rate in time series is not considered, only the failure rate in the failure rate field 30b may be used for failure risk evaluation.

  The failure risk calculation device 32 stores the failure risk calculated in this way for each network device 14-1 to 14-n in the failure risk DB 34. FIG. 6 shows the structure and data example of the failure risk DB 34. The failure risk DB 34 includes a device ID field 34a, a unit time failure risk field 34b, a failure risk field 34c after one month, a failure risk field 34d after two months, and a failure risk field 34e after three months. In addition, the failure risk per unit time and the failure risk on the time axis for each of the network devices 14-1 to 14-n are retained.

  The unit time failure risk field 34b stores the result of multiplying the failure loss amount by the failure rate in the failure rate field 30b of the failure rate / failure rate DB 30. The failure risk field 34c when one month has elapsed stores the result of multiplying the loss amount during failure by the failure occurrence rate in the failure occurrence rate field 30c when one month has elapsed in the failure rate / failure occurrence rate DB 30. The failure risk field 34d after two months stores the result of multiplying the loss amount during failure by the failure occurrence rate in the failure occurrence rate field 30d when two months have elapsed in the failure rate / failure occurrence rate DB 30. In the failure risk field 34e when 3 months have elapsed, the result of multiplying the loss amount at failure by the failure occurrence rate in the failure occurrence rate field 30e when 3 months have elapsed in the failure rate / failure occurrence rate DB 30 is stored.

  Based on the failure risk information stored in the failure risk DB 34, for each network device 14-1 to 14-n, the expected value of the loss caused by the failure based on the actual usage mode (transmission / reception traffic amount and presence / absence of redundancy) is known. be able to.

  The display processing device 36 displays failure risk information in the failure risk DB 34 on the display device 40 in accordance with a user instruction input by the input device 38. For example, when the user instructs the display processing device 36 to display a list of network devices 14-1 to 14-n whose failure risk is equal to or higher than a certain value by the input device 38, the display processing device 36 will display the failure risk DB 34. A list of network devices 14-1 to 14-n having a failure risk that meets the conditions is created and displayed on the display device 40.

  FIG. 7 shows a schematic block diagram of the second embodiment of the present invention. In this embodiment, a plurality of network devices (accommodating devices for accommodating users) 114-1 to 114-3 are connected in a hierarchical structure as illustrated in FIG. 8, and the subscriber devices 116-1 to 116-3 are connected to each other. Applies to network configurations that connect to those terminations. In the present embodiment, as a loss amount when a failure occurs in the network devices 114-1 to 114-3, the subscriber device 116-1 under the control due to a communication failure due to the failure of the network devices 114-1 to 114-3. The sum of the damage amount suffered by ˜116-3 is used.

  The repair time / redundancy presence / absence DB 120 of the failure risk evaluation apparatus 110 is similar to the repair time / redundancy presence / absence DB 20 for the accommodation devices 114-1 to 114-3 and the subscriber devices 116-1 to 116-3 shown in FIG. Data is stored.

  The subscriber information DB 122 stores data as shown in FIG. 9 for the subscriber devices 116-1 to 116-3. FIG. 9 shows the structure and data example of the subscriber information DB 122. The subscriber information DB 122 is located on the path until the subscriber ID field 122a for identifying the subscriber devices 116-1 to 116-3 and each subscriber device reaches a predetermined base port (hierarchy route). A storage device ID field 122b for storing the ID of the storage device, a monthly usage fee field 122c, and an importance field 122d are provided. The importance in the importance field 122d is set in advance by the operator in consideration of the urgency / importance of information exchanged by each subscriber, the contract service level of each subscriber, and the like.

  In the example shown in FIG. 9, the accommodation device ID field 122b exemplifies a lower accommodation device ID and a higher accommodation device ID. This is an example corresponding to FIG. When a plurality of routes can exist up to the base point port, the accommodation device ID on the route is recorded in the accommodation device ID field 122b for each route, and the presence of a plurality of routes means redundancy for each accommodation device. It means that it is made redundant as a root.

  The loss amount estimation device 126 replaces each of the accommodated devices 114-1 to 114-3 registered in the repair time / redundancy presence / absence DB 120 with the subscriber terminals 116-1 to 116-3 that are disconnected in the event of a failure. It searches with reference to the accommodation apparatus ID field 122b of subscriber information DB122.

  In order to facilitate understanding, in the example shown in FIG. 8, when each of the accommodation devices 114-1 to 114-3 is not configured redundantly, the following is performed. That is, when the accommodating device 114-3 fails, communication between the subscriber devices 116-2 and 116-3 directly accommodated in the accommodating device 114-3 is interrupted. When the accommodation device 114-1 breaks down, there is no subscriber device directly accommodated by the accommodation device 114-1, but the subscriber is accommodated via the subordinate accommodation devices 114-2 and 114-3. Communication between the devices 116-1 to 116-3 is interrupted.

ここで、Ｎは、当該収容機器の故障により通信が断絶する加入者機器の数である。また、「冗長の有無」の項の意味は、実施例１の場合と同じである。 The loss amount estimation device 126 reads the monthly usage fee (field 122c) and importance (field 122d) of the subscriber affected by the failure from the subscriber information DB 122 for each accommodated device, and the usage fee per hour. Calculate the product of (= monthly usage fee / 720 hours) and importance, and take the sum. This sum is multiplied by the repair time / redundancy presence / absence DB 120, the repair time of the accommodation equipment and the presence / absence of redundancy (“Yes” = 0 / “No” = 1), and the multiplication result C _charge is the amount of loss. And That is,

Here, N is the number of subscriber devices whose communication is interrupted due to a failure of the accommodation device. Further, the meaning of the term “redundancy” is the same as in the first embodiment.

  The loss amount estimation device 126 stores the estimated loss amount in the failure loss amount DB 128. Loss-on-failure DB 128, failure rate / failure occurrence rate DB 130, failure risk calculation device 132, failure risk DB 134, display processing device 136, input device 138, and display device 140 operate in the same manner as in Example 1. Since it is the same as DB 28, failure rate / failure occurrence rate DB 30, failure risk calculation device 32, failure risk DB 34, display processing device 36, input device 38, and display device 40, description thereof will be omitted.

By applying this embodiment to a large-scale network, the failure risk of each node can be calculated quantitatively, and efficient device replacement becomes possible. Specifically, the loss due to the failure of the network device can be reduced by exchanging the devices in descending order of the risk of failure. This embodiment can be used as a part of a network management system for a communication carrier having a large-scale network.
As a quantitative evaluation of the loss when a failure occurs, the amount of traffic lost when a failure occurs in the device and the subscriber's damage taking account of the usage fee and importance are illustrated. Others can be used as the loss amount.

  Although the invention has been described with reference to specific illustrative embodiments, various modifications and alterations may be made to the above-described embodiments without departing from the scope of the invention as defined in the claims. This is obvious to an engineer in the field to which the present invention belongs, and such changes and modifications are also included in the technical scope of the present invention.

It is a schematic block diagram of one Example of this invention. It is a block diagram of the network system which connects the Example shown in FIG. It is a structure and data example of DB for repair time and redundancy. It is a structure and data example of loss amount DB at the time of failure. It is a structure and data example of failure rate and failure occurrence rate DB. It is a welfare commission and data example of the failure risk DB. It is a schematic block diagram of the second embodiment of the present invention. It is an example of network device connection to which the second embodiment is applied. It is a structure and data example of subscriber information DB.

Explanation of symbols

10: Failure risk evaluation device 12: Network 14-1 to 14-n: Network device 20: Repair time / redundancy presence / absence database 20a: Device ID field 20b: Repair time field 20c: Redundancy presence / absence field 22: Device information collection device 24: Network interface 26: Loss amount estimation device 28: Loss amount database 28a at failure: Device ID field 28b: Loss amount field 30: Failure rate / failure occurrence rate database 30a: Device ID field 30b: Failure rate field 30c: When one month has elapsed Failure occurrence rate field 30d: failure occurrence rate after 2 months field 30e: failure occurrence rate after 3 months field 32: failure risk calculation device 34: failure risk database 34a: device ID field 34b: failure risk per unit time Field 34c: Failure risk field after one month elapses 34d: Failure risk field after two months elapse 34e: Failure risk field after three months elapse 36: Display processing device 38: Input device 40: Display device 110: Failure risk evaluation device 114-1 to 114-3: Accommodating equipment (network equipment)
120: Repair time / redundancy presence / absence database 122: Subscriber information database 122a: Subscriber ID field 122b: Accommodating device ID field 122c: Monthly usage charge field 122d: Importance field 126: Loss amount estimation device 128: Loss amount database at failure 130: Failure rate / failure rate database 132: Failure risk calculation device 134: Failure risk database 136: Display processing device 138: Input device 140: Display device

Claims (3)

A repair time / redundancy presence / absence database (20) in which the repair time of each device and the presence / absence of redundancy are recorded for a plurality of devices constituting the system;
For the plurality of devices, the failure rate / failure rate database (30) in which the failure rate and failure rate of each device are recorded,
A loss amount estimating means (26) for calculating a loss amount in the case of failure of the device;
Failure risk calculation means (32) for referring to the failure rate / failure occurrence rate database and calculating the expected loss value at the time of failure of the device as the failure risk from the loss amount of each device estimated by the loss amount estimation means When,
A failure risk database (34) for recording the failure risk of each device calculated by the failure risk calculation means;
A failure risk evaluation apparatus comprising: display means for displaying the contents of the failure risk database. Furthermore, the device is a network device, and comprises device information collection means for periodically collecting the transmission / reception traffic amount of the lower ports of the plurality of devices,
The failure risk evaluation apparatus according to claim 1, wherein the loss amount estimation unit estimates, as a loss amount, a transmission / reception traffic amount lost in the event of failure of each device. In addition, for each subscriber, a device that directly accommodates the subscriber, a device that is positioned above the device, a subscriber information database in which information on usage charges and importance is recorded,
2. The failure risk evaluation according to claim 1, wherein the loss amount estimation means estimates, as a loss amount, a quantitative evaluation of a damage amount suffered by a subordinate subscriber due to a communication failure caused by a failure of each device. apparatus.

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