Buffers

A buffer is in (logical of physical) inventory point for a item at a certain location.

Different types of buffers exist:

  • Default:
    The default buffer uses an “producing” operation to replenish it with additional material.
  • Infinite:
    An infinite buffer is unconstrained and has an infinite supply of the material.
    Propagation through a bill of material will be stopped at an infinite buffer.

Fields

Field Type Description
item item
Item being stored in the buffer.
This is a required field.
location location
Location of the buffer.
This is a required field.
The working hours and holidays for the buffer are taken from the ‘available’ calendar of the location.
description string Free format description.
category string Free format category.
subcategory string
Free format subcategory.
If this field is set to ‘tool’, the field ‘tool’ will automatically be set to true.
onhand double
Inventory level at the start of the time horizon.
Default is 0.
minimum double
Desired minimum inventory, aka safety stock.
Use this field if the safety stock doesn’t change over time.
The solver treats this as a soft constraint, ie it tries to meet this inventory level but will go below the minimum level if required to meet the demand.
A problem is reported when the inventory drops below this level.The safety stock target is expressed as a quantity. If you want to define a safety stock target as a time value (aka days of inventory), you can set a post-operation timeon the producing operation of the buffer.
minimum_calendar calendar
Refers to a calendar storing the desired minimum inventory level, aka safety stock.
Use this field when the minimum inventory level is varying over time. Otherwise use the minimum field. If both fields are specified, the minimum field is ignored.
maximum double
Refers to a calendar storing the maximum inventory level.
This field is not used by the solver.
A problem is reported when the inventory level is higher than this limit.
maximum_calendar calendar
Refers to a calendar storing the maximum inventory level.
Use this field when the maximum inventory level is varying over time. Otherwise use the maximum field. If both fields are specified, the maximum field is ignored.
tool boolean
A flag to mark buffers that are actually representing a tool.
Default is false.
The impact on the planning results is visible in the pegging and criticality calculations.
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