Forecasting Overview
Forecasting requires you to project the future requirements for an item
based on your past usages of the item, sales predictions, etc. This topic
describes how MRP and APS plan forecasts as independent requirements and
how existing demands, such as customer orders, consume the forecasts.
Creating a Forecast
You create a forecast for a given item on the Forecast
form. Enter the Original Quantity to specify the quantity you are forecasting
a need for (the "demand quantity"). Enter the Forecast Date
to represent the due date of the forecast. Enter the Warehouse to forecast
for a specific warehouse. If you have elected to create independent requirements
based on customer orders (see Use Customer
Order or Forecast for more information), then you may also specify
a customer when creating a forecast.
About the Use CO or Forecast Planning Parameter
The Use
CO or Forecast parameter on the Planning
Parameters form determines whether the system plans forecasts and/or
customer orders as demands/requirements. For example, if this parameter
is set to Forecast, customer orders are not planned and the system uses
the forecast's Original Quantity as the demand quantity instead of using
the Outstanding Requirement. All examples in this help topic assume the
Use CO or Forecast field is set to Both.
CAUTION: If the
Use Co or Forecast parameter is set to Both, and you change either the
Forecast Look Ahead or Forecast Look Behind parameter values, the system
may reevaluate forecast consumption for all items, and this process may
take a long time.
How Forecasts are Planned
When you initially create the forecast, the value in the Outstanding
Requirement field equals the value in the Original Quantity field. Existing
demands (such as customer orders entered before you run the MRP Planning or APS
Planning activity) consume the forecast quantity from this Original
Quantity value. The Outstanding Requirements value reflects the remaining
forecast quantity that will drive independent requirements for planning
(for both MRP and APS). See "How Existing Demands Consume the Forecast"
below for details about which demands can consume the forecast quantity.
The process the system uses to plan forecast requirements is different
depending on whether you are running MRP or APS.
How MRP Plans Forecasts
MRP plans forecasts according to this process:
- Plans the Outstanding Requirement quantity from forecasts (and
quantities from other independent requirements, such as customer orders)
for a given end item.
- Searches for existing on-hand and receipts to satisfy the requirement.
- Creates a planned order for the net requirement after on-hand inventory
and planned supplies have been considered.
- "Explodes" this net requirement from the planned order
through the item's bill of material, creating the dependent requirements
for the component materials. See MRP
Overview for more information.
NOTE:In SyteLine (PROGRESS)
MRP, the planning parameter "CO and Forecast On Line" updated
the forecast consumption information automatically whenever you added,
changed, or deleted a forecast or customer order. In SyteLine (SQL), this
functionality is in place by default (due to the SQL database table structure).
For example, if you add a new forecast, that forecast will be visible
immediately on reports and output forms without requiring you to rerun
MRP.
How APS Plans Forecasts
APS plans forecasts according to this process:
- Plans the forecast before or after planning other demands according
to your APS
order priority.
- Allocates any available on-hand inventory and planned supplies
(within Supply
Usage Tolerance), further reducing the forecast quantity to be
planned. Keep in mind that other demands such as customer orders will
probably have priority over forecasts for using on-hand inventory
and planned supplies, depending on how your order priorities are set.
- Explodes, as required, the net requirement from the planned order
through the BOM for this demanded quantity of the item.
- Generates planned orders at all levels needed to satisfy the remaining
forecast quantity. The forecasted item's planned order's Projected
Date indicates the availability date of the forecast supply.
New incoming demands can use this forecast's supply only after the planning
run is complete, when you incrementally
plan them during a save or Get ATP/CTP process.
NOTE: If a demand
consumes a forecast, any subsequent Get ATP/CTP process you perform on
that demand will consider this consumption of forecasted supply in the
calculation of the Projected date.
EXAMPLE:
For this example, assume these conditions:
- On-hand inventory: 150
- Forecast-XYZ Original Quantity: 200
- Priority for customer orders on the APS Order Priority form
is set so the system plans customer orders before it plans forecasts.
You enter a customer order for a quantity of 120. The customer order
consumes the forecast (assume the customer order is due within the
Forecast Look Behind/Ahead window). The forecast's Outstanding Requirement
is reduced to 80.
You then run APS Planning. The system first plans the customer order
demand. It allocates the on-hand inventory to the customer order,
satisfying the order and leaving a remainder of 30 on hand. Then the
system plans the forecast demand. It allocates the remaining 30 from
inventory and generates a planned order for 50 to satisfy the remaining
forecast demand.
How Existing Demands Consume the Forecast
The Forecast
Look Behind and Forecast
Look Ahead parameters specified on the Product
Codes form and/or on the Planning Parameters
form set up a time window within which existing customer orders and other
demands can consume a forecast. The system uses this window when searching
for a forecast to place a customer order against. The search for a forecast
works as follows:
- The system tries to locate a forecast for the same date as the
demand's due date. The system ignores old forecasts if the Forecast
Date is more working days into the past than the current date + the
Forecast Look Behind value.
- If a forecast matching the demand's due date does not exist or
is already consumed (an Outstanding Requirement equal to zero), the
system starts at the demand's due date minus Forecast Look Behind
and searches for a forecast up to the demand's due date plus Forecast
Look Ahead.
- If the system finds a matching forecast, it checks whether the
forecast is already consumed. If the forecast has been consumed, the
system locates the next valid forecast.
- If the demand quantity is greater than the Outstanding Requirement,
the system sets the Outstanding Requirement to zero, and applies the
remaining demand quantity to the next valid forecast. If the system
does not find a valid forecast, the demand does not consume any forecasts.
- On the Forecast
form, Customer and Warehouse are optional forecast fields that also
influence the process by which demand is matched to a given forecast.
The search is performed in this order:
- On Customer and Warehouse
- On Warehouse only when Customer is null
- On Customer only when Warehouse is null
- On forecast records when Customer and Warehouse are both null
EXAMPLE:
For this example, assume these conditions:
Forecast Look Ahead: 7
Forecast Look Behind: 4
Forecasts for:
50, due 10/1
60, due 10/5
50, due 10/9
50, due 10/13
Customer orders (COs) for:
20, due 9/20
20, due 9/25
10, due 10/2
15, due 10/5
30, due 10/15
25, due 10/17
- For the CO on 9/20: there is no forecast for 9/20, so searching
starts from 9/16 through 9/27. No forecast is found, so this CO
does not consume a forecast.
- For the CO on 9/25: there is no forecast for 9/25, so searching
starts from 9/21 through 10/2. There is a forecast for 10/1. The
system subtracts 20 from Outstanding Requirement, leaving 30.
- For the CO on 10/5: there is a forecast for 10/5. The system
subtracts 15 from Outstanding Requirement, leaving 45.
- For the CO on 10/15: there is no forecast for 10/15, so searching
starts from 10/11 through 10/22. There is a forecast for 10/13.
The system subtracts 30 from its Outstanding Requirement, leaving
20.
- For the CO on 10/17: there is no forecast for 10/17, so searching
starts from 10/13 through 10/24. There is a forecast for 10/13.
The system subtracts only 20 from the Outstanding Requirement
because that is all that remains. The remaining five are subtracted
from the next available forecast.
NOTE: If forecasts
appear at multiple levels in a bill of material, a forecast for a parent
material cannot consume the supply from the forecast for a child material
(unless the child forecast generates excess quantity because of an Order Minimum
specification, in which case the excess quantity can be used).
Related Topics
APS Overview
Forecast
MRP Overview
Planning Parameters
About Intra-Site
Transfers