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Parallel Replenishment calculation setup approaches
Automatic Replenishment consists of three important calculation processes to make proposals for purchases and transfers to stores or warehouses:
- Out of Stock calculation
The Out of Stock calculation detects on item, variant, location, and day level occurrences of out of stock situations.
This serves two purposes:- Information about occurrence and duration of out of stocks.
- Input for the Replenishment Item Quantity and Replenishment Journal calculation, since out of stock days are treated differently in the demand calculation.
This process is optional
but if it is required, it needs be executed first before the other processes. - Replenishment Item Quantity (RIQ) calculation
The RIQ calculation takes a snapshot of the current stock situation and the open sales orders, transfer orders, and purchase orders. - Replenishment Journal calculation
The Replenishment Journal calculation uses the RIQ information and calculates demand and proposals for transfers and purchases.
The calculation time of these processes is directly dependent on the number of items, variants, and locations to be calculated. The calculation can be quite time consuming, if there are large numbers of items and locations involved.
The calculation performance can be improved using parallel calculation. The concept is to run the Out of Stock, RIQ, and Replenishment Journal calculations in parallel, where the items are split and shared across multiple sessions so that they are calculated in parallel to speed up the calculation of the process.
Parallel Replenishment calculation setup approaches
There are three ways in how the parallel calculation can be set up: using NAS service tiers, background sessions, or Job Queues.
Using NAS service tiers
In a classical setup, a NAS service tier is used to process a Scheduler job. In the parallel approach, more NAS are added so that the workload can be distributed among the additional services.
This approach is applicable for the LS Central on-premises environment and the supported processes are Out of Stock and RIQ calculations.
For more information on how to set up the parallel calculation for Out of Stock and RIQ using NAS service tiers, see Parallel Replenishment Calculation Memo (LS Central 20.0).pdf.
Using background sessions
With this approach, the system spins up multiple background sessions based on the parallel jobs configuration, and each background session processes a part of the entire item scope.
It supports all three processes: Out of Stock, RIQ, and Replenishment Journal calculations, and can be used both in LS Central on-premises and SaaS environments. This approach is easy to set up but there is, however, an operational limit set by Microsoft for Business Central SaaS, where there are only maximum 10 background sessions per environment that can be processed at the same time in a server instance. Background sessions that come in when this limit is exceeded wait in a queue until a time slot becomes available. For more information, see Operational limits for Business Central online.
To set up the parallel calculation using background sessions:
For Out of Stock and RIQ calculations, see Parallel Replenishment Item Quantity and Out of Stock Calculations.
For Replenishment Journal calculation, see Parallel Replenishment Journal Calculation.
Using Job Queues
When the Out of Stock, RIQ, or Replenishment Journal calculation is initiated, the system creates multiple Job Queue entries based on the parallel jobs configuration, and each Job Queue entry processes a part of the entire item scope. Unlike the background session, this approach is not limited to 10 parallel sessions, but do take note that one user can only start and run a maximum of five Job Queue entries simultaneously. Therefore, you must set up more users in your environment if you want to run more than five parallel sessions. For more information, see Operational limits for Business Central online.
The Job Queue approach supports all three processes: Out of Stock, RIQ, and Replenishment Journal calculations, and can be used both in LS Central on-premises and SaaS environments.
To set up the parallel calculation using Job Queues:
For Out of Stock and RIQ calculations, see Parallel Replenishment Item Quantity and Out of Stock Calculations.
For Replenishment Journal calculation, see Parallel Replenishment Journal Calculation.
See also
Replenishment Out of Stock Days
Calculation of Replenishment Item Quantity