Statistics for Maintenance Modelling: Continuous Lifetime Distributions 1

# Calculating the Poisson Distribution Using Excel¤

The Excel function:

POISSON(x,mean,cumulative)

calculates the Poisson probabilities. The parameters of this Excel function are:

- x is the number events
- mean in our notation is lambda * t
- cumulative is false if it's the probability of observing "x" events that you require and true if you require the probability of observing "x" or fewer events.

Hence if lamdba * t = 0.1, the probabilities of observing 0 events and the probabilities of observing 1 event are given by:

- Poisson(0, 0.1, false) = 0.904837
- Poisson(1, 0.1, false) = 0.090484

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