Outlining Warehouse Structures

Since SAP EWM is connected to an ERP system, there are organizational units that we must consider on both sides (ERP and EWM). Inventory management takes place in the ERP system and stock is stored in a plant at storage location level.

A plant is a location where goods are produced (manufacturing plant) or stored (distribution center) and where services are provided. A plant is assigned to a company code, which is a Financial Accounting organizational unit. Storage locations are assigned to a plant and keep the stock in view of inventory management. Because of this, at least one storage location is necessary.

Having different storage locations in a plant allow you to:

• Differentiate between the various stocks of material in a plant
• Differentiate between the physical storage characteristics
• Classify the quantities of material in a plant to indicate their use (for example, available for sale) or perhaps their logical location (for example, at a third-party logistics provider)

A storage location does not include any physical substructures. This is done with a warehouse number. A warehouse number can refer to a single building, or several individual warehouse buildings, that together, form a complete warehouse complex.

Although SAP EWM is very different than SAP WM, both use a warehouse number to represent the physical warehouse in which materials are stored and managed. This warehouse number must be created in ERP customizing. In the case of the use as an SAP EWM warehouse, a substructure does not need to be configured for this warehouse in ERP. Instead, the ERP warehouse number is set up as SAP EWM relevant, and connected to a warehouse number that is defined in SAP EWM. In the ERP system, the warehouse number is a three-character field. However, in SAP EWM, it is a four-character field.

These organizational units and structures are generally the same in SAP S/4HANA, also when using embedded EWM.

To activate warehouse management in the ERP system, a plant and a storage location (for that plant) is linked with the respective warehouse number.

The warehouse number is the highest level of organizational unit in warehouse management. The organizational and physical attributes of a warehouse building are entered under the warehouse number in Customizing. Examples of some attributes are:

• Weight unit of measure
• Volume unit of measure
• Time unit of measure

There are also various determination procedures for palletization data and packaging specifications that are assigned at the warehouse number level.

In practice, the warehouse number usually corresponds to a physical building or distribution center. If your warehousing facilities are located in different cities or are physically separated by a long distance, it is appropriate to assign a separate warehouse number to each warehouse complex.

To each warehouse number a unique Supply Chain Unit (SCU) with the Business AttributeINV - Warehouse must be assigned. An SCU is a physical or organizational unit that is used within a logistics process, with one or more business attributes. The supply chain unit contains essential information, such as country, region, and time zone. The system uses the time zone of the SCU for the warehouse number when displaying all date and time fields.

Each warehouse number has a substructure that maps the spatial relationship in the warehouse complex in detail.

A storage type is a physical or logical subdivision of a warehouse complex. It is characterized by:

• Warehouse technologies
• Space required
• Organizational form or function

The storage type is a four character code that is defined when customizing SAP EWM. Storage types have a storage type role that defines what they are used for.

Storage type roles and their purposes are outlined in this table.

Essential settings regarding putaway, stock removal or goods movement control are configured in the storage type customizing.

A storage section is an organizational subdivision of a storage type. It is assigned to storage bins that have similar attributes. This information is then used during the putaway process. The criteria for joining these bins (or the attributes of the bins) can be defined in any way, for example:

• Heavy parts
• Bulky parts
• Hazardous materials with certain characteristics
• Fast-moving items
• Slow-moving items

Besides that, storage sections are required in staging areas groups (which are storage types, which are used for goods receipt and goods issue).

A storage bin is the smallest addressable unit of space in a warehouse and it represents the exact position in the warehouse at which a product can be stored.

As the address of a storage bin is frequently derived from a coordinate system, that address is called a bin coordinate. A bin coordinate is 18-characters in length, for example, the coordinate 01-02-03 would be a storage bin in aisle 1, stack 2, and level 3. Note that the bin coordinate assigned to a storage bin is unique within the warehouse.

1. Define the bin coordinate structure or "coding" by assigning a unique character to represent these components of the bin coordinates:
   • Aisle
   • Stack
   • Level
   • Bin subdivision
   • Bin depth
2. Use this coding to create templates to generate the storage bin master data automatically.

You can use any combination of letters and numbers for storage bin coordinates. Ensure that you organize each part of the structure according to the coding defined for your warehouse (for aisle, stack, level, and so on).

Each storage bin must be assigned to a storage type and can be assigned to a storage section.

You can also define additional attributes for a storage bin such as:

• Storage bin type: Used to indicate the relative size of a bin and/or actual bin dimensions.
• Bin access type: Used to control how a bin is accessed by resources.
• RF verification field: Used in (radio frequency) RF scanning to verify that the correct bin is being accessed.
• Geo-coordinates of storage bin: Used by SAP EWM to compute distances between the bins in goods movements.
• Capacity checking attributes (max weight, volume, total capacity): Used to control the amount of product to be stored in a bin.
• Fire containment section: Used in product hazardous material reporting.

Warehouse activities, for example putaway, picking, and physical inventory, are executed in activity areas. This allows the sequence of warehouse tasks to be optimized according to the assignment of storage bins to an activity area.

You create activity-dependent bin sortings within an activity area.

An activity area consists of one or more assigned storage bins. Depending on the activity, the same storage bin can be assigned to multiple activity areas. For each activity, the assigned bins are sorted per activity area.

For the sorting, you use information from the storage bin, such as, the aisle, the stack, or the level as sort criteria.

To optimize the picking or putaway process, storage bins are logically grouped using the activity area.

It is important to point out that activity areas are not mandatory - with one exception, for physical inventory. Picking or putway can also be done in a bin which is not assigned to an activity area for the specified activity. But activity areas are very important instruments to control the workload of warehouse resources.

The graphical warehouse layout shows a two-dimensional view of the inside of the warehouse. This includes the stock situation and information regarding storage bins, resources, and automatic storage retrieval.

The dimensions of the storage bins are displayed based on Bin Type definition and the X, Y, and Z coordinates.

Stock stored in a storage bin is called a quant. A quant represents the quantity of a specific product in a single storage bin, a resource, or a transportation unit.

If a batch-managed material is stored in a single storage bin, then the system counts each batch as a different quant.

During putaway, when you put a product into an empty bin in EWM, the system generates a quant in that storage bin. You can increase the quantity of a quant by adding to the existing stock. When you remove the quantity from storage, the system automatically deletes the quant.

In the quant record, the system manages the data for the products in a quant. That data includes:

• Quant identification (assigned by the system)
• Product number
• Batch number
• Stock type
• Stock usage