# Simulation

Simulate a rule or analysis version with manually entered values to check the result before publishing it. The simulation writes nothing: it does not change events, lists or analysis windows. Any version can be simulated, including a draft, by any access profile.

A [connected agent](/en/admin/agent/#operations) runs the same simulations.

## Simulate a rule

In the version menu, select **Simulate…**:

1. Under **Variables**, fill in the fields the rule reads.
2. If the rule runs an analysis, choose the analysis windows.
3. Select **Simulate**.

The analysis windows define the history each analysis run reads:

| Windows                | Behavior                                                                     |
| :--------------------- | :--------------------------------------------------------------------------- |
| **Live**               | the account's accumulated history, as in a real run                          |
| **Empty**              | no history; counts start at zero and proportions do not produce a score      |
| **Supplied values**    | each cell uses the entered value; a blank cell is evaluated with no history  |

With **Supplied values**, the screen shows one field per cell of each analysis. A count cell takes an integer from 0. A proportion cell takes the **Percentage**, from 0 to 100, and the **Sample**, from 1. The trigger and the score are still calculated from each cell's configuration. The values are only used if the condition that runs the analysis is met.

### Result

The result reports which condition was met and is split into four tabs:

| Tab               | Content                                                                                          |
| :---------------- | :----------------------------------------------------------------------------------------------- |
| **Fields**        | values the actions would write to the event                                                      |
| **Transients**    | [temporary variables](/en/rules/expression-syntax/#temporary-variables-) produced during the run |
| **Unevaluated**   | cells left out of the decision, with the reason                                                  |
| **Execution**     | each condition, met or not, and the lists, analyses and enrichments queried by a met condition   |

An unevaluated cell takes no part in the decision, and the absence of a trigger does not indicate low risk. The reasons are **Not enough data to score**, **Dimension has no value in the event** and **Window unavailable**.

When an action replaces or clears an entered value, the screen shows a notice under the corresponding field. The conditions that follow read the new value.

### What the simulation runs

The simulation reproduces the real run, with the following differences:

| Action or query                                                             | In the simulation                                                         |
| :-------------------------------------------------------------------------- | :------------------------------------------------------------------------ |
| [Set field](/en/rules/actions/set_field/) and the temporary variable actions | write only to the simulation's memory                                    |
| [Run analysis](/en/rules/actions/run_analysis/)                             | reads the real windows, except with **Empty** or **Supplied values**      |
| [Enrich](/en/rules/actions/enrich/) and [list](/en/rules/lists/) queries    | query the real data, read only                                            |
| [Add to list](/en/rules/actions/add_to_list/) and [record analysis](/en/rules/actions/record_analysis/) | are not run; the result shows them as actions not executed |

A version in [observation](/en/rules/versioning/#observation) is simulated against the windows of the analysis in observation. The simulation does not count toward the runs nor toward the [conditions met](/en/rules/versioning/#conditions-met).

## Simulate an analysis

In the analysis version menu, select **Simulate…**:

1. Under **Dimensions**, fill in the fields the cells group the windows by. A cell with any blank dimension is not evaluated.
2. Choose the analysis windows, with the same options as the [rule simulation](#simulate-a-rule).
3. Select **Simulate**.

The **Cells** card shows one row per cell:

| Column      | Content                                                                          |
| :---------- | :------------------------------------------------------------------------------- |
| **Name**    | the cell's name and measure, with the **Triggered** and **Decided** marks, when they apply |
| **Window**  | the cell's accumulation period                                                   |
| **Threshold** | the cell's trigger; blank on a [no-trigger cell](/en/rules/analyses/#no-trigger) |
| **Score**   | the cell's score; blank on a no-trigger cell                                     |
| **Value**   | measured value                                                                   |
| **Sample**  | number of observations                                                           |
| **Source**  | where the value comes from                                                       |

The **Source** column takes one of these values:

| Source            | Origin                                                            |
| :---------------- | :---------------------------------------------------------------- |
| **Window**        | the account's real window                                         |
| **Supplied**      | value entered in the simulation                                   |
| **No history**    | empty windows, or a blank cell under **Supplied values**          |

In a draft, a cell created in this version shows the notice **New in this version. Starts with no history once published.** The cells that come from an earlier version keep the windows' history, as described in [Analysis versions](/en/rules/versioning/#analysis-versions).

The **Result** card indicates the cell that triggered the analysis and shows the values a rule receives when running this version: the score, the score cell, and the count and names of the triggered cells. The corresponding keys are in [Run analysis](/en/rules/actions/run_analysis/).