Category: Business CentralRead time: 5 MinsPublished on: 06 Feb 2026

Planning Parameters in Business Central: Complete Guide to MRP, Reordering Policies & ATP/CTP

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Planning parameters in Microsoft Dynamics 365 Business Central control how the Business Central planning engine (MRP/MPS) generates supply suggestions in the Planning Worksheet and Requisition Worksheet. These settings on the Item Card and Stockkeeping Unit (SKU) Card Planning FastTab determine when the system creates Action Messages such as New, Reschedule, Change Quantity, or Cancel.

During a Calculate Regenerative Plan, Business Central evaluates demand from sales orders, production orders, forecasts, and transfers to propose optimal purchase or production orders. Correct configuration ensures accurate Available-to-Promise (ATP) and Capable-to-Promise (CTP) dates while preventing excess inventory and emergency procurement.

For organizations looking to implement or fine-tune these settings, our Business Central consulting services help configure planning parameters, MRP logic, and replenishment strategies aligned with real operational demand.

Planning Execution Flow in Business Central

Planning suggestions in Business Central are created through the Planning Worksheet (for manufacturing and MRP) or the Requisition Worksheet (for purchase planning). The planner runs Calculate Regenerative Plan or Calculate Net Change Plan, and the system generates Action Messages based on the planning parameters defined on the Item or SKU Card.
These suggestions are finalized using Carry Out Action Message, which converts them into purchase orders, production orders, or transfer orders. The behaviour of every suggestion is directly controlled by the reordering policy, dampener settings, safety stock, and order modifiers explained below.

1. Recording Policy

The Reordering Policy field on the Item Card Planning FastTab is the primary driver for MRP (Material requirements planning) logic in Business Central. It defines how the planning engine groups demand, creates supply orders, and displays suggestions in the Planning Worksheet lines.

  1. Fixed Reorder Quantity

    Fixed Reorder Quantity is typically used for high-demand items with consistent consumption, where stock availability must be always maintained. When the inventory level falls to or below the defined minimum threshold, Business Central automatically creates a replenishment order for a predefined, fixed quantity. In the Planning Worksheet, this policy always proposes a New action message with the predefined quantity, regardless of the exact shortfall calculated by MRP

    For example, Consider Coffee powder, which is consumed regularly and must always be available. Assume Coffee powder has a minimum stock level of 10 kg. When the quantity drops to 10 kg, Business Central automatically creates a purchase order for a fixed quantity—say 50 kg—regardless of the exact remaining balance. This ensures that rice is replenished in bulk and is always available without frequent small purchases.

    Visit Reordering in Business Central to know more about managing inventories efficiently.

  2. Maximum Quantity

    Maximum Quantity policy is used for frequently consumed items where inventory replenishment is restricted by warehouse limitations, such as available storage space or carrying costs. Instead of ordering a fixed quantity, the system replenishes stock only up to a defined maximum level, helping prevent overstocking while ensuring uninterrupted availability.

    For example, consider coffee in an office pantry where storage space is limited. The maximum inventory level is set to 30 kg and the minimum level is 5 kg. When stock drops to 5 kg, Business Central calculates the required purchase quantity to refill inventory up to the maximum limit. In this case, the system generates an order for 25 kg, ensuring optimal stock levels without exceeding storage capacity or increasing holding costs.

    The system calculates the required quantity as Maximum Inventory – Projected Available Balance, which is displayed as the suggested quantity in the Requisition Worksheet.

  3. Order

    Order reordering policy is typically used for high-value, A-level items that are not stocked in advance and are procured or produced only based on specific customer requests. These items are often customized, expensive to hold, or ordered infrequently, making it inefficient to maintain regular inventory levels.

    For example, consider a custom coffee machine ordered by a customer with specific features. Since this is a one-off request and the item is costly to store, Business Central does not trigger any automatic replenishment based on inventory levels. Instead, the item is ordered or produced only when a confirmed sales order exists, ensuring zero excess stock and better cost control.

    With this policy, MRP creates supply only when a specific demand line exists, and the Planning Worksheet shows a direct one-to-one link between the sales order and the proposed purchase or production order.

  4. Lot-for-Lot

    Lot-for-Lot is the default policy recommended by Microsoft for most items because it works seamlessly with Net Change Planning and respects Lot Accumulation Period and Rescheduling Period. The system groups demand within the defined period and generate a single suggestion in the Planning Worksheet instead of multiple small orders.

    With this policy, Business Central generates replenishment orders that exactly match the required demand for a given planning period but process them as a grouped quantity rather than individual orders. This supports economic inventory handling by avoiding one-by-one purchasing or production.

    For example, consider coffee cups used in an office or cafeteria. Demand is regular, and the cost per unit is moderate. Instead of ordering cups individually for each requirement, Business Central groups the demand and creates a single purchase order for the total required quantity. When applied to purchase orders, the lot size can be configured to take advantage of bulk discounts while still aligning closely with actual demand.

  5. Parameters
    • Include Inventory

    Determines whether existing inventory is included in the projected available balance during replenishment planning. This setting influences the Projected Available Balance visible in the Planning Worksheet and determines whether existing on-hand stock is deducted before creating new supply.

    • Lot Accumulation Period

    Specifies the period during which demand is consolidated into one replenishment order under the Lot-for-Lot policy.

    • Rescheduling Period

    Specifies a period within which any suggestion to change a supply date always consists of a Reschedule action and never a Cancel + New action. When this period is exceeded, Business Central generates Cancel + New action messages instead of Reschedule, which increases order churn.

2. Reserve

The Reserve field controls whether inventory is exclusively reserved for specific demand, such as sales orders or production orders, or whether it remains freely available for general use. It determines how strictly Business Central links supply (inventory, purchase orders, production orders) to demand. Reservation is different from Order Tracking Policy were reservation locks inventory, while order tracking only creates informational links used by MRP.

  • Never
    It is not possible to reserve the item.
  • Optional
    You can reserve the item manually.
  • Always
    The item is automatically reserved from demand, such as sales orders, against inventory, purchase orders, assembly orders, and production orders.

3. Order Tracking Policy

The Order Tracking Policy field determines how Business Central tracks and links supply orders (purchase orders, production orders, transfers) with demand documents (sales orders, service orders, or production consumption). Unlike reservations, order tracking is informational, it provides traceability without locking inventory. Order Tracking links are visible in the Order Tracking page from sales, purchase, and production documents and are used by planners to analyze how demand is covered before running Carry Out Action Message.

  • None
    No tracking is performed. Supply and demand remain independent, offering maximum flexibility but minimal visibility.
  • Tracking Only
    Business Central creates dynamic links between supply and demand to show how requirements are covered. These links are for planning and visibility only and do not reserve inventory.
  • Tracking & Action Msg.
    In addition to tracking supply and demand, Business Central generates action messages (such as delay, or reschedule) when changes occur, helping planners respond proactively.

4. Dampener Period

Dampener Period helps avoid unnecessary changes to purchase or production orders within a defined time frame. It ensures that minor short-term fluctuations in demand do not trigger frequent rescheduling, reducing manual interventions and improving planning stability. Dampener Period directly affects the Reschedule action message in the Planning Worksheet by suppressing date changes that fall within the defined window.

Scenario: Managing Purchase Orders in an Electronics company

  • A company manufactures and sells LED TVs.
  • A purchase order is scheduled for March 10 to produce 5,000 LED TVs.
  • Due to a spike in demand, the system recalculates and suggests rescheduling the order to March 8.
  • The Dampener Period is set to 5 days.
  • Result - The new suggested date (March 8) falls within the dampener period (March 5 – March 10), the system does not change the order.
  • A company manufactures and sells LED TVs.
  • A production order is scheduled for March 10 to produce 5,000 LED TVs.
  • The new suggested date was March 3.

Result - the new suggested date is outside the dampener period, the system would recommend rescheduling the order.

5. Dampener Quantity

Dampener Quantity helps reduce unnecessary purchase or production order modifications when small quantity fluctuations occur. It ensures that minor changes in demand do not trigger frequent order adjustments, which can lead to inefficiencies and increased administrative workload.

Scenario: Managing Orders in an Electronics Warehouse

  • A company manufactures and sells LED TVs.
  • The existing production order is for 1,000 units.
  • Due to changing market demand, the system calculates that the required quantity should be 1,010 units.
  • The Dampener Quantity is set to 20 units.

Result - Since the difference (10 units) is less than the dampener quantity (20 units), the system does not modify the order.

  • A company manufactures and sells LED TVs.
  • The production order is for 500 units.
  • The Dampener Quantity is set to 50 units.
  • Required quantity had increased to 600 units

Result - the difference (100 units) is higher than the dampener quantity (50 units), the system suggests us to modify the order.

6. Critical

A critical field refers to a key parameter that directly influences how the system calculates and commits to order fulfilment dates. Business Central calculates delivery promises using the Order Promising page, which evaluates:

  1. Available-to-Promise (ATP) – Based on current stock and incoming supplies.
  2. Capable-to-Promise (CTP) – Considers production or procurement lead time to determine when an item can be delivered.
  1. Available-to-Promise (ATP)

    ATP calculates the earliest date an item can be shipped based on existing inventory and confirmed replenishment orders. It does not consider manufacturing or additional procurement.

    Scenario: A distributor of laptops receives a new order.

    • Current stock: 50 units
    • Incoming purchase order: 100 units arriving in 3 days
    • Customer orders 40 units today

    Result: Since 50 units are available, the system suggests an immediate delivery.

  2. Capable-to-Promise (CTP)

    CTP calculates the earliest possible shipment date, including manufacturing or procurement lead time, when stock is insufficient.

    Scenario: A manufacturer of custom furniture receives an order.

    • Current stock: 0 units
    • Production lead time: 10 days
    • Raw materials available: Can start production immediately

    Result: System suggests to a delivery date in 10 days, considering the time required for production.

7. Safety lead time

Safety Lead Time is a buffer period added to planned receipts of items to account for unexpected delays in procurement, production, or transportation. It helps prevent stockouts and ensures a smoother supply chain by compensating for uncertainties like supplier delays, production bottlenecks, or shipping disruptions. Safety Lead Time is added to the Due Date Calculation during MRP and is visible in the Planning Worksheet as the adjusted receipt date.

Safety Lead Time is added to the Due Date Calculation during MRP and is visible in the Planning Worksheet as the adjusted receipt date.

When calculating replenishment, Business Central extends the expected receipt date by the Safety Lead Time, ensuring that materials arrive before they are needed.

Scenario: Managing Raw Materials for a Car Manufacturer

Company: A car manufacturer orders engine components from an overseas supplier.

  • Lead Time from Supplier: 20 days
  • Unpredictable Customs Delays: Possible 5-day delay
  • Safety Lead Time Set: 5 days
  • Total Planned Lead Time: 25 days (20 days lead time + 5 days safety lead time)

Result - Instead of planning the component's arrival exactly 20 days later, the system adds a 5-day buffer.

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8. Safety Stock Quantity

Specifies a quantity of stock to have in inventory to protect against supply-and-demand fluctuations during replenishment lead time.

Example:
Consider bottled water in an office. On average, the office consumes 50 bottles per week. However, during hot weeks, client events, or sudden staff gatherings, consumption can rise unexpectedly, and sometimes deliveries may be delayed.

To avoid running out, the office sets a Safety Stock Quantity of 20 bottles. This ensures that even if demand suddenly increases or delivery is late, there is still enough water available until the next replenishment arrives.

9. Reorder Point Parameters

Reorder point parameters help automate inventory replenishment by defining when and how much to order for items that are consumed regularly. These parameters ensure that stock is replenished before it runs out, balancing availability with storage and carrying costs. These fields are used mainly with Fixed Reorder Quantity and Maximum Quantity policies and drive automatic suggestions in the Requisition Worksheet.

  • Reorder Point
    The minimum inventory level that triggers a replenishment order.
  • Reorder Quantity
    The fixed quantity to be ordered once the inventory reaches the reorder point.
  • Maximum Inventory
    The upper limit of stock you want to maintain, preventing overstocking.
  • Overflow Level
    The inventory level above which no further replenishment is planned, even if demand exists.
  • Time Bucket
    The period over which demands are grouped or averaged to calculate replenishment needs.

10. Order Modifiers

Order modifiers control the size and structure of replenishment orders, ensuring they comply with supplier, production, or warehouse constraints. They help optimize inventory handling, reduce costs, and take advantage of bulk ordering or packaging requirements.

  • Minimum Order Quantity
    The smallest quantity that can be ordered in a single replenishment.
  • Maximum Order Quantity
    The largest quantity that can be ordered at once, preventing overstocking.
  • Order Multiple
    The quantity must be a multiple of this value, often used to match supplier packaging or production batch sizes.

Order Modifiers are applied after MRP calculation but before the suggestion appears in the Planning Worksheet, ensuring compliance with supplier packaging and production batch rules.

Need help configuring planning parameters, MRP, and replenishment strategies in Business Central? Contact our experts to design a stable, cost-efficient planning setup for your business.