addDemand {FaultTree}

Add a Pure Demand Event

Description

Modifies an existing fault tree with the addition of a pure demand event.

Usage

addDemand(DF, at, mttf, tag="", label="", name="", name2="", description="")

Arguments

DF

A fault tree dataframe such as returned from ftree.make or related add... functions.

at

The ID of the parent node for this addition.

mttf

The mean time interval to events. It is the user's responsibility to maintain constant units of time.

tag

A very short identifying string (typically 5 characters or less) uniquely identifying a basic event for minimal cutset evaluation

label

An identifying string for the logic gate. Use of label in ftree.make defines the convention for rest of tree construction.

name

A short identifying string (typically less than 24 characters)

name2

A second line, if needed for the identifying string label

description

An optional string providing more detail for the resultant event.

Value

Returns the input fault tree dataframe appended with an entry row for the defined component event. Note that when a pure demand is used in combination under an AND gate, the result will contain only a conditional fail rate.

References

Nicholls, David [Editor] (2005) System Reliability Toolkit Reliability information Analysis Center

O'Connor, Patrick D.T. (1991) Practical Reliability Engineering John Wiley & Sons

Vesely, W.E., Goldberg, F.F., Roberts, N.H., Haasl, D.F. (1981) Fault Tree Handbook U.S. Nuclear Regulatory Commission

Vesely, W.E., Stamatelato, M., Dugan, J., Fragola, J., Minarick, J., Railsback, J. (2002) Fault Tree Handbook with Aerospace Applications NASA

Doelp, L.C., Lee, G.K., Linney, R.E., Ormsby R.W. (1984) Quantitative fault tree analysis: Gate-by-gate method Plant/Operations Progress Volume 3, Issue 4 American Institute of Chemical Engineers

Examples

mytree <-ftree.make(type="and")
mytree <- addDemand(mytree,  at=1, mttf=1, name="power interruption")