- 105 Views
- Uploaded on
- Presentation posted in: General

Approach: Fault tree analysis

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Approach: Fault tree analysis

E0 – Top event: operational failure or life-safety failure (two trees)

E0

Ei – Basic event: damage of individual equipment

E23

“or” - gate

“and” - gate

E1

E2

E3

(E0 occurs) if and only if (E1occurs OR both E2 and E3 occur)

E0

E23

E1

E2

E3

Mathematical equivalent of gates (independent events):

O

I1

IN

O

IN

I1

For the example fault tree:

Events of interest and proposed Decision Variables (DV):

- Life safety failure: DVLS=P(LSF | T), where LSF is
- Occurrence of a life-threatening event, T = planning period (alternatively: DVLS=P(LSF|IM))

- Operational Failure: DVO=P(OF | T) or P(OF | IM), where OF is
- Repair or replacement time of critical equipment exceeds some threshold value DT0.
- Research products lost and the time to repeat the study is greater than some threshold value RT0.

Required performance level is specified by DVLS, DVO, DT0, RT0

Operational Failure

To be refined upon consulting Comerio’s database, Comerio and LSA occupants

Subject Die

Critical Equipment Failure

Data Lost

Env. Failure

Trauma

Microscope

is broken

Data storage

device is broken

Temp. Changes

Containment Failure

Basic event

(Damage State)

Hazmat Release

Tube is broken

- Result of calculation of DV=P(E0 | IM) by applying theorem of total probability

- Result of calculation of DV=P(E0 | EDP)

1.0

1.0

DV

DV

0.0

0.0

x1

x2

x3

x1

x2

x3

IM

IM

Each point corresponds to a particular value of the vector of EDP at the given level of IM

Where N – is number of simulations at the level IM=xi, and the right part probabilities are all conditioned on IM= xi

GM ID

SIM #

EDP ID

EDP Value

Files in formats: CSV, MDB, XLS.

Fragility Parameters

DS

Assembly ID

Assembly Name

EDP Type

P1 (e.g. )

P2 (e.g. )

Files in formats: CSV, MDB, XLS.

- Result of simulation of E0| EDP, using generated El events

- P(E0 | EDP), using generated El events

1.0

E0

DV

n1

n2

m3

n3

m2

m1

0.0

x1

x2

x3

x1

x2

x3

IM

IM

- Generate basic event Eiaccording to distribution P(El | EDP = Vk)
- Follow Boolean logic of the fault tree to know if E0has happened
- Repeat for all Vk , and get ni, mi for each level of excitation IM=xi

Where mi – is number of simulations when E0 has happened, and ni – is number of simulations when E0 has not happened