Materials Planning Procedures in SAP (MRP & CBP)




You should read previous post about materials planning overview before reading this post. In this article we will explain in detail about materials planning procedure in SAP R/3. Its basic concept is similar with other inventory control software, but SAP R/3 has its own unique procedures for materials planning.

Basically, there are two types of standard materials planning procedures in SAP, which are:

1. Traditional Material Requirements Planning (MRP)

In traditional SAP MRP system, sales order, planned independent requirements, reservations, dependent requirements that are created by BOM explosion, and so on are planned directly as requirements. The materials planning procedure will create procurement proposal only if these requirements will result in shortage of material stocks at a certain time. There are no other requirement that can trigger a procurement proposal. This procedure is used in “PD-MRP” MRP Type in standard SAP R/3.
MRP is especially useful for the planning of finished products and important assemblies and components (A materials).


2. Consumption Based Planning (CBP)
Consumption-based planning (CBP) is a materials planning procedure based on past consumption values that determine future requirements by using forecast or other statistical procedures.

Originally, in CBP, planned independent requirements or dependent requirement will not be considered in the net requirements calculation. Instead, it is triggered when stock levels fall below a predefined reorder point or by forecast requirements calculated using past consumption values. So, all the planned independent or dependent requirements in a certain period of time should have been considered before (when set the reorder point or calculate the requirement forecast).

Consumption-based planning procedures are simple materials planning procedures which we can use to achieve set targets with relatively little effort. Therefore, these planning procedures are used in areas without in-house production and/or in production plants for planning both B- and C-parts and operating supplies.

There are three procedures in Consumption Based Planning (CBP), which are:

a.Reorder point planning
In reorder point planning, SAP checks whether the available stocks are below the reorder point that has been set for the material. If they are, SAP will create procurement proposal.

We can determine the reorder point manually (“VB-Manual reorder point planning” MRP Type in standard SAP R/3) or, it can also be calculated automatically using the material forecast (“VM-Automatic reorder point planning” MRP Type in standard SAP R/3).

The reorder point should cover the average material requirement/consumption expected during the replenishment lead time (procurement processing time + planned delivery time + GR processing time). Besides the average consumption, we also should consider safety stock. The safety stock exists to cover both excess material consumption within the replenishment lead time and any additional requirements that may occur due to delivery delays. Therefore, the safety stock is included in the reorder level.

The following values are important for defining the safety stock:

 

  • Past consumption values (historical data) or future requirements
  • Vendor/production delivery timelines
  • Service level to be achieved
  • Forecast error, that is, the deviation from the expected requirements

In standard SAP R/3 system, besides “VB – Manual Reorder Point” and “VM – Automatic Reorder Point” MRP Type, there are also other MRP Types that have reorder point as its basis to calculate requirement with additional procedure which count external requirement (sales order and manual reservation) as a requirement. The MRP Type are: “V1-Manual reorder point with external requirements” and “V2-Automatic reorder point with external requirements”.

b.Forecast-based planning
In forecast-based planning, historical data is used in the material forecast to estimate future requirements. These requirements are known as forecast requirements and are immediately available in planning.

The forecast, which calculates future requirements using historical data, is carried out at regular intervals. This offers the advantage that requirements, which are automatically determined, are continually adapted to suit current consumption needs.

This procedure is used in “VV-Forecast-based planning” MRP Type in standard SAP R/3.

c.Time-phased materials planning
In time-phased planning, historical data is also used in the material forecast to estimate future requirements. However, in this procedure, the planning run is only carried out according to predefined intervals. If a vendor always delivers a material on a particular day of the week, it makes sense to plan this material according to the same cycle, in which it is delivered.
This procedure is used in “R1-Time-phased planning” MRP Type in standard SAP R/3.

Besides all procedures that have been explained above, in SAP R/3 system we can create other procedures according to our own needs. We can do it through configuration with SPRO T-code.

We will write another post about how to configure MRP in SAP R/3 System. Please come back later.


14 thoughts on “Materials Planning Procedures in SAP (MRP & CBP)

  1. Thanks for the wonderful explanation. Does help me in understanding some basic. However i have a question which am not certain with.

    If i have a product with a MRP TYPE VM, do i still need to enter the reorder point qty manually so that system would able to compare it with the actual stock level to generate a PR ?

  2. Hi,
    For VM MRP Type, you need to enter the reorder point manually first with a reasonable value although it will be replaced by system then.

    When you execute forecast (MP30), the system will automatically calculate the Reorder Point and safety stock and update them on the material master.

    Prerequisites: to allow system calculate it, you must enter this information before in the material master:
    1.Total replenishment lead time (RLT) – MRP-3 view
    2.Service Level – MRP- 2 view

  3. Hi,

    Thanks for the useful post.

    I need to know if we want to replenish the articles on the basis of its sales then which steps we have to follow.

    Please help in this.
    regards
    Amar

  4. Thanks, this was really very useful information.

    Can you please advise how order quantity will be calculated? Do we need to specify order quantity in any of the MRP input views and if so which one and can you please explain it a bit in details.

  5. Hi Kaybee,
    You can define it in "Lot Size" field at the Lot Size Data section in MRP 1 view of the material master data.

    There are some options, such as:
    EX: Lot for lot
    FX: Fixed Order Qty
    HB: Replenish to maximum stock level
    etc.

  6. If the purchase request will be only created when I get customer’s sale order, which MRP type should I choose for this material PD or ND? May I know the difference between PD and ND?
    thanks!
    Lucia

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