Forecasts let you include anticipated future demand when calculating purchase requirements in the Enhanced Planning Worksheet.

Business Central uses demand forecasts to represent expected demand before actual orders exist. For standard Business Central planning, forecasts are netted against actual demand so the same demand isn’t planned twice. For more information, see Create a demand forecast.

The Enhanced Planning Worksheet applies forecasts when you run Calculate Purchase Plan.

Selecting a forecast

On the Calculate Purchase Plan request page, use:

• Forecast Name to select the Business Central demand forecast to include.
• Forecast End Date to limit how far into the future forecast demand is considered.

If no Forecast Name is selected, forecast demand isn’t included in the Purchase Plan.

For the other Purchase Plan options, see Enhanced Planning Worksheet.

How forecast demand is calculated

The Purchase Plan considers both actual demand and forecast demand.

For each SKU, it calculates:

1. Actual demand, including applicable sales, service, and transfer demand.
2. Forecast demand from the selected forecast.
3. Actual sales usage is deducted from the forecast for the applicable forecast period to determine the remaining forecast demand.
4. The Purchase Plan then uses the greater of actual demand or the remaining forecast demand when calculating the requirement.

This prevents forecast demand and the actual sales that fulfill that forecast from both being counted as separate requirements.

For example, if a period contains:

• Forecast demand: 100
• Actual sales usage against the forecast: 40
• Total applicable actual demand: 40

The remaining forecast requirement is 60, so the Purchase Plan uses 60 as the demand to plan for rather than adding 100 forecast units and 40 actual units together.

If actual demand instead exceeds the remaining forecast requirement, the actual demand is used.

Forecasts and standard Business Central planning

Calculate Purchase Plan doesn’t replace standard Business Central MPS or MRP planning. It is a separate SKU-based calculation focused on purchases and transfers.

Microsoft describes how forecasts are used in the standard planning engine in Run Full Planning, MPS, or MRP and About planning functionality.

For more information about how the Enhanced Planning Worksheet differs from standard Business Central planning, see Planning Concepts and Parameters in the Enhanced Planning Worksheet.

For details about the complete Purchase Plan calculation, see How does the Planning Worksheet Purchase Plan calculate the amount to purchase?.