FailureModel

R2026b

Event failure model in fault tree document

Since R2026b

Description

FailureModel objects represent event failure models in Safety Analysis Manager fault tree documents. Use FailureModel objects to configure how your events occur.

Creation

To create a FailureModel object:

• Use the createFailureModel or getFailureModel function on a FaultTreeDocument object.

• Get the FailureModel property from an Event object.

Properties

Type — Type of failure model

"constant" | "rate" | "time-at-risk" | "mttf" | "dormant" | "logical"

Type of failure model, specified as one of these options:

Value	Description	Supported Events
"constant"	The failure probability and failure frequency are independent and constant.	Basic Undeveloped
"rate"	The failure probability has an exponential relationship with the evaluation time, the failure rate is constant, and the failure is repairable. The failure model calculates the failure frequency by using the failure probability.	Basic Undeveloped
"time-at-risk"	The failure probability has an exponential relationship with a specified exposure time, and the failure rate is constant. The failure model calculates the failure frequency by using the failure probability.	Basic Undeveloped
"mttf"	The model calculates a failure probability and failure rate by using a mean time to failure (MTTF) and a mean time to repair (MTTR). MTTF and MTTR are constant. The failure model calculates the failure frequency by using the failure probability.	Basic Undeveloped
"dormant"	The failure rate is constant, however the failure is not known until the failed artifact is tested. Testing occurs at a fixed interval. The failure model calculates the failure frequency by using the failure probability.	Basic Undeveloped
"logical"	The failure is either active or not. The failure does not have a rate or frequency.	Basic Undeveloped House

For more information on the implementations of each failure model type, see Create Fault Tree Events.

Label — Failure model label

"MODEL" (default) | string scalar | character vector

Failure model label, specified as a string scalar or character vector. Each failure model must have a unique label. If you create another failure model with the default label, the next addition uses the default label with an appended number. Each new failure model increments the number, for example, MODEL1, MODEL2, and so on.

Data Types: char | string

Description — Failure model description

"" (default) | string scalar | character vector

Failure model description, specified as a string scalar or character vector.

Data Types: char | string

Shared — Whether failure model is shared

false or 0 (default) | true or 1

Whether the failure model is shared in more than one event, specified as a numeric or logical 0 (false) or 1 (true). If you assign the failure model to more than one event, this property becomes 1. Once you assign the failure model to more than one event, you cannot change this property unless you reassign the failure model to one event or no events.

Data Types: logical

Parameters — Failure model parameters

Read-only: FailureModelParameters object

This property is read-only.

Failure model properties, represented as a FailureModelParameters object. The properties of the FailureModelParameters object depend on the Type property value.

DependentEvents — Events that use failure model

Read-only: array of Event objects

This property is read-only.

Events that use this failure model, represented as an array of Event objects.

Object Functions

addFlag	Add flag to Safety Analysis Manager spreadsheet cell or row
acceptAllChanges	Accept detected changes to linked artifacts in Safety Analysis Manager
clearFlags	Clear flags in Safety Analysis Manager spreadsheet and fault tree document elements
getChanges	Get changed artifacts linked to artifacts in Safety Analysis Manager
getFlags	Retrieve flags from Safety Analysis Manager documents
getLinks	Get links associated with spreadsheet cell or row in Safety Analysis Manager
navigate	Navigate to elements in Safety Analysis Manager documents and changed artifacts

Examples

Create Failure Model in Fault Tree Document

Create a fault tree document in the Safety Analysis Manager.

myTreeDoc = safetyAnalysisMgr.newDocument("fault-tree");

Add a failure model to the fault tree document.

myFailureModel = createFailureModel(myTreeDoc);

Retrieve Failure Model from Event

Create a fault tree document in the Safety Analysis Manager and retrieve the FaultTree object.

myTreeDoc = safetyAnalysisMgr.newDocument("fault-tree");
myFaultTree = myTreeDoc.FaultTrees(1);

Add two basic events to the tree.

myTopGate = myFaultTree.Gates(1);
event1 = createEvent(myTopGate);
event2 = createEvent(myTopGate);

Retrieve the failure model from event1.

myFailureModel = event1.FailureModel;

Version History

Introduced in R2026b