# How To Use Forecast Simulation

## Objective

Estimate how incoming demand and available capacity could affect backlog over a selected time horizon.

## Environment

- You have access to a generated forecast with incoming volume for the dates you want to simulate.
- You know which queues and backlog statuses to include and have a capacity assumption to test.

## Resolution

1. Open the forecast and select **Simulation**. Review the latest forecast date and any warnings before changing assumptions.
2. Select an existing simulation from the selector, or keep **Unsaved simulation** to start a new scenario. Use the refresh control to recalculate after changing inputs.
3. Set the scenario assumptions. Choose a **Capacity source**; with **Manual entry**, set capacity for each queue and weekday in the table. Choose whether **Tickets/hr from** uses the **Profile** or **Measured** value. Set **Volume change %** to model a demand increase or decrease, **Horizon (days)** for the length of the simulation, and **Clear backlog in (days)** for the target time to work through the opening backlog.
4. Select the **Backlog statuses** to include, such as **New**, **Open**, **Pending**, or **Hold**. Review each queue’s starting backlog and tickets per hour, then enter the daily capacity values you want the simulation to test.
5. Read the result cards and **Backlog burn-down** chart. **All workload cleared** indicates whether the selected work is cleared within the horizon; **Peak backlog** shows the largest simulated backlog; **Idle capacity** shows capacity left unused; and **Required hours** reports whether the target clearance time is achievable. The chart compares forecast inbound volume, remaining opening backlog, unserved incoming work, and capacity.
6. Change one assumption at a time and recalculate to see how it affects the results. Select **Save** to keep a named simulation for later review.

Use the simulation as a scenario estimate. Its result depends on the selected forecast, statuses, productivity assumption, and capacity entries; confirm the inputs and forecast coverage dates before using it to make staffing decisions.

> Canonical page: https://zenops.cx/help/articles/use-forecast-simulation/
> Audience: For planners and managers
> Summary: Explore how backlog and capacity assumptions affect a forecast scenario.

## Notes on this article

### Important: Check the forecast coverage window

After step 1 in resolution. The simulation uses forecast inbound volume only through the dates covered by the forecast. Later days may simulate zero arrivals; this does not mean actual demand will be zero. Check the coverage dates before interpreting backlog clearance or capacity results.

## Visual references

- The Simulation tab combines backlog and capacity assumptions with a forecast horizon, result cards, and a backlog burn-down chart.: [Forecast Simulation tab showing backlog cleanup settings, capacity source, volume change, horizon, backlog statuses, a queue capacity row, result cards, warnings, and a backlog burn-down chart.](https://zenops.cx/help/assets/forecast-backlog-simulation.png)