As the name suggested, JMeter Poisson Random Timer is used to generate and add the random delay before the execution of a sampler. This timer is based on the Poisson Distribution Function. The delay (think) time is the sum of the Poisson distributed value multiplied by defined lambda value and the offset value.

**How to add ‘Poisson Random Timer’?**

Follow the below steps:

- Select the appropriate element where you want to add the timer
- Test Plan
- Thread Group
- Controller
- Sampler

- Right-click on the element
- Hover the mouse on ‘Add’
- Hover the mouse on ‘Timers’
- Click ‘Poisson Random Timer’

## What are the inputs for ‘Poisson Random Timer’?

‘Poisson Random Timer’ has the following input fields:

*Name**:*To provide the name of the timer*Comments**:*To provide arbitrary comments (if any)**Lambda (in milliseconds)****:**The number shows how much the delay can deviate from the given offset towards the higher and lower range.The number shows a constant delay which will be added to the random number generated by Poisson Function in the range of given deviation value.**Constant Delay Offset (in milliseconds):**

## Example:

If Constant Delay Offset is given 1000 and Lambda is given 200 then Poisson Random Timer will generate the random number in the range of 800 to 1200 milliseconds:

**Poisson Random Timer Delay = 1000 + PF*200 **

where PF value could be from -1 to 1

### Additional Information:

- The Poisson Random timer is processed before each sampler in the scope in which it is found; if there are several timers in the same scope, all the timers will be processed before each sampler.
- Timers are only processed in conjunction with a sampler. A timer which is not in the same scope as a sampler will not be processed at all.
- To apply the timer to a single sampler, add the Poisson Random Timer as a child element of the sampler.
- To apply the timer after a sampler, either add the Poisson Random Timer as a child element of the next sampler or as a child element of Flow Control Action.