SAP MM ECC vs S/4HANA: Key Changes and Simplifications

 ECC vs S/4 HANA in SAP MM — What You Really Need to Understand

To help every consultant, whether they are Functional, Technical, or a Project Manager, understand the shift from ECC to S/4HANA MM, we need to focus on the "Big Six" changes.

Think of this as moving from an old, fragmented system to a streamlined, high-speed engine.

 

1. The "Unified ID": Business Partner (BP)

In ECC, you had separate screens for Vendors (XK01) and Customers (XD01).

• S/4HANA Reality: Everything is a Business Partner (BP).
• Easy understanding: Imagine you have one "Profile" (the BP) and you simply assign different "hats" to it. One hat is the Supplier role (for MM), and another is the Customer role (for SD).
• Why it matters: It eliminates duplicate data. You no longer have to create the same company twice if you both buy from and sell to them.

2. The "Single File": MATDOC Table

In ECC, inventory data was messy. A single Goods Receipt was saved in many different tables (like MKPF for the header and MSEG for the items).

• S/4HANA Reality: All logistics movements now live in one single table: MATDOC.
• Easy understanding: Instead of keeping your receipts in five different folders, you now have one master digital ledger.
• Why it matters: It makes reporting 100x faster. When you search for stock history, the system only has to look in one place.

3. The "Supercar" Engine: MRP Live

In ECC, Material Requirements Planning (MRP) was a heavy process. You usually ran it overnight because it slowed down the system.

• S/4HANA Reality: MRP Live (MD01N) runs directly on the HANA database, not the application layer.
• Easy understanding: MRP moved from a slow "tractor" to a "Formula 1" car. It calculates what you need to buy in seconds.
• Why it matters: You can run MRP many times a day. If a L'Oréal warehouse in Paris suddenly runs out of shampoo, MRP Live can detect it and suggest a purchase order almost instantly.

4. The "Name Tag": 40-Character Material Number

In ECC, the Material Number (MATNR) was limited to 18 characters.

• S/4HANA Reality: You can now have up to 40 characters.
• Easy understanding: You have more space to name your products.
• Why it matters: This is a "Technical Warning." If you have custom ABAP code (Z-programs) written for 18 characters, they might break. Technical consultants must check this during the migration.

5. The "Smartphone" Interface: Fiori

In ECC, we used the SAP GUI with Transaction Codes like ME21N. It looked like software from the 1990s.

• S/4HANA Reality: We use Fiori Apps.
• Easy understanding: It’s like moving from an old flip phone to an iPhone. Instead of typing T-codes, you click on "Tiles."
• Why it matters: You can approve Purchase Orders on your phone or tablet while traveling. It also gives you "Alerts"—the system tells you when a vendor is late, instead of you having to run a report to find out.

6. The "Smart Rules": Output Management (BRF+)

In ECC, if you wanted to print a PO or send an email to a vendor, you used "NAST" (Output Types). It was rigid and hard to configure.

• S/4HANA Reality: The new standard is BRF+ (Business Rule Framework plus).
• Easy understanding: It’s a "Decision Tree" for your documents.
• Why it matters: It is much more powerful. You can set complex rules like: "If the PO is for a Luxury Brand and the amount is > €50k, send an encrypted PDF; otherwise, send a standard EDI."

 

⚖️ Summary for the Team

Point	ECC MM (The Old Way)	S/4HANA MM (The New Way)
Vendor	Separate "Vendor" master data.	Unified Business Partner (BP).
Data	Data scattered in MSEG, MKPF, etc.	Data centralized in MATDOC.
Speed	Overnight MRP runs.	Real-time MRP Live.
Length	18 chars for Material ID.	40 chars for Material ID.
Look	Grey screens and T-codes.	Modern Fiori Apps and Tiles.
Prints	Old NAST configuration.	Intelligent BRF+ rules.

 

 

 

Stock types supported in SAP S/4HANA

 

                       Stock type is the term used in SAP to designate the disposition or usability of the stock for materials planning and execution purposes.

 

There are 4 main stock types supported in SAP S/4HANA:

 

1.    Unrestricted use stock

2.    Quality inspection stock

3.    Blocked stock

4.    Customer returns stock

 

Unrestricted Use Stock:

                 The unrestricted use stock type is used to designate inventory quantities that are free to be considered for materials planning or execution purposes, such as deliveries to customers or consumption for production. Unrestricted use stocks can be freely transferred between plants and storage locations.

 

Quality Inspection Stock:

                The quality inspection (QI) stock type is used for identifying quantities of goods that are undergoing processing by the quality department at the current time. QI stocks are considered available from a materials planning point of view. However, these stocks can't be shipped to a customer or consumed internally until a decision has been made about their usability.

 

Ø  The QI stock can be transferred between storage locations in a plant but can't be transferred between plants.

 

Ø  QI stocks may be under the control of the Quality Management (QM) module.

Ø  If QM is active for that material in that plant, then Quality Management processes control the postings of material into and out of the QI stock type.

 

Ø  If QM isn't active for that material in that plant, then transfer postings are used to post stocks out of QI stock into unrestricted use stock.

 

Blocked Stock:

                   The blocked stock type is used when a material becomes unusable for planning and execution purposes. Blocked stocks generally aren't considered during materials planning.

 

Ø  Blocked stocks can't be used for fulfilling customer or production demands.

Ø  Blocked stocks can be transferred between storage locations within a plant.

 

Ø  Note that unrestricted use, quality inspection, and blocked stocks are considered valuated stocks if the stock type assigned to the material is valuated in the valuation area assigned to the plant.

 

Customer Returns Stock:

                           The customer returns stock type is a less commonly used stock type. It can be used to manage goods that have been delivered back into a storage location from a customer when a decision hasn't been made as to whether the goods will be accepted back into stock.

 

Ø  Customer returns stock is always non valuated stock.

Ø  Once a decision is made to accept the goods, a transfer posting from customer returns to either unrestricted use, quality inspection, or blocked stock is made. This transfer posting posts the quantities into valuated stock and creates an accounting document.

Special Stocks & Ownership:

 In SAP S/4HANA system are owned by the enterprise and are reflected in the appropriate stock accounts in Financial Accounting.

However, it's possible to represent stocks that are owned by an external party in the system.

Special stock indicators are used to represent these ownership scenarios in Inventory Management.

 

Each special stock has a unique one-letter identifier in the database.

 

The following are examples of special stocks that are owned by the enterprise and

physically stored at an external location:

 Ø  Component stocks provided to supplier for subcontracting (special stock 0)

 Ø  Finished goods consigned to a customer (special stock W)

  Ø  Returnable transport packaging at customer (special stock V)

Note that these special stocks can be in either unrestricted use or quality inspection stock types.

 The following are examples of special stocks owned by an external party and physically stored in a plant and storage location:

 Ø  Supplier consignment stock (special stock K)

Ø    Supplier-owned returnable transport packaging (special stock M)

Subcontracting in SAP S/4 HANA

              In previous versions of SAP ERP, component materials to be provided to the subcontractor could be planned as a separate stock. However, with SAP S/4HANA, a subcontracting MRP area is the default option for subcontracting planning. Subcontracting will appear under the general plant stock if there is no MRP area maintained for the supplier.
 
Also, in previous versions of SAP ERP, We could check subcontracting stocks by supplier
by running reports from a specific IMG menu path. This transaction is now available as an app (Display Subcontracting Stocks by Supplier) in SAP S/4HANA
 
 
Ø  In SAP S/4HANA, MRP areas have to be created for every subcontractor.

Ø  If MRP area specific material master records don't exist, MRP uses default planning parameters.

Ø  This differs from classic SAP ERP for subcontracting, in which we could plan either with or without MRP areas.

Ø  If we elected to plan without MRP areas, we weren't able to use the full functionality around lot sizing and were only able to order full lot sizes.
 
Ø  If we chose the MRP area route, material data on an MRP area was required for all
components. These two options are now combined into one driven by MRP areas, but it doesn't require material data on all components and can support full-lot sizing and sourcing functionality.
 
Upgrading MRP Subcontracting to SAP S/4HANA
To upgrade MRP subcontracting processes in SAP ERP to SAP S/4HANA, we need to
take stock of your existing subcontracting suppliers and processes and identify any
gaps, execute a standard upgrade to SAP S/4HANA, and then at postprocessing proceed
as follows:
 
1. Maintain subcontracting MRP areas for all subcontracting suppliers requiring provision
stocks to be planned separately from requirements. The customizing entry in the supplier master is sufficient to trigger stock transfers and reservations from the plant to the subcontracting MRP area.
 
we only have to maintain entries in the material masters if special situations exist for lot sizing, purchase requisitions/ orders, and/or third-party order processing.
 
2. Run regenerative MRP and test.
 

Find the Transaction code that is replaced by a new Transaction code in SAP S/4 HANA

This is very important to know what are the Transaction Codes that are replaced with new Transaction Codes 

These steps will be very helpful for every Consultant that are moving to SAP S/4 HANA.

 Steps: Go to Transaction Code SE16-> Enter table PRGN_CORR2

 Now enter REL_NAME Field as 751 like below and Execute

The S_TCODE is Replaced by T_TCODE Column or field value

now we will get the list.

Example: MBXX replaced  with MIGO

Example: XDXX,XKXX,MKXX,FKXX replaced  with BP