R/2-R/3 Link 

The R/3 Warehouse Management (WM) link to R/2 provides the capability for customers who already have an SAP R/2 host system to manage all warehousing activities using the R/3 System user interface.

The Four-Level Model

The architecture of a modern, automated warehouse system can be displayed in the form of a four-level model in which four systems fulfill different tasks.

Level 1: The Host System

On the first level is a central EDP system (also called the host system). The host system carries out the functions of inventory management and material requirements planning.

Level 2: The R/3 WM System

On the second level is a Warehouse Management (WM) system that manages the storage bins and determines which material transfers need to be executed.

Level 3: The WCU system

On the third level is a Warehouse Control Unit (WCU) in an automated warehouse that converts the transfer requirements of the WM system into commands for the conveyor equipment, puts these in an optimal sequence, and then monitors them.

Level 4: The PMC system

On the fourth level there is a Programmable Memory Control (PMC) system for the conveyor equipment that executes the conveyor commands.

SAP Components in the Four-Level Model

The first two levels are supported in the SAP system:

Computer Configuration

Each level can either run on its own system or several levels can run on the same system.

Central R/2 Warehouse Management System

The term "central" Warehouse Management applies if WM runs in R/2 on the host system or in R/3 in the client-server architecture as an integrated application.

R/2-R/3 Link

It is also possible to install WM as an R/3 system on its own computer separately from the R/2 System so that the WM functions can be carried out independent of the availability of the R/2 system.

Communication Between the Levels

Even if the different levels run on separate computers, they need to be able to communicate with one another. The interface between the different computers should not be set up as a rigid connection because data needs to be transferred continuously - as in an integrated application.

In this guide, we discuss the communication between an R/2 host system (1st level) and an R/3 Warehouse Management system (2nd level).

Advantages of the R/2-R/3 Link

The advantages of a system that runs as an R/3 application separate from the other R/2 applications (Inventory Management, Sales, Production) include the following:

24-Hour Availability

The production department of many companies are frequently in operation two or three shifts per day. This means that operating hours in the warehouse are longer as well. On the one hand, the production department must be supplied with the necessary raw materials and other supplies that are stored in the warehouse. On the other hand, finished products must be transferred from production to the warehouse for storage.

For this reason, the R/3 Warehouse Management system needs to be available 24 hours a day. Pallets can then be taken from production, for example, and placed into storage even if the host system is not available.

Reduction of System Load in the Host

The host system is relieved of all warehousing functions. System performance can thus be improved.

Independence from the Host System

It is possible to work with the R/3 WM system even if the host is not available (for example, if the host system shuts down unexpectedly).

If the host system is not available, it is still possible to create transfer orders in the R/3 system. The corresponding goods receipts or goods issues messages to the host are stored temporarily and then sent as soon as the host becomes active again.

If there are any breakdowns in the host system, these do not affect transactions carried out in the R/3 WM system.

R/3 User Interface

The R/3 WM system offers the same user-friendly CUA user interface as the integrated version of WM in the R/3 system.

Automatic Reposting

Some goods movements postings in the R/3 System are automatically carried over to the R/2 System.

Working with Two systems Simultaneously

You can work with both systems simultaneously at one screen. You log on to the R/3 application through your terminal and also have access to the host system via the CUA interface. For example, you can post a goods movement in the R/2 Inventory Management system using one window and, after the posting is complete, you create the corresponding transfer order in the R/3 Warehouse Management system in another window.

Integration in the Overall System

The R/2 WM system runs on a host computer with all other R/2 components (for example, Inventory Management, Material Requirements Planning, Production, Accounting).

R/3 WM is installed on a separate system (for example, under UNIX). In addition to WM, other basic components are required for processing in R/3.

The R/3 WM system communicates with the R/2 host system, that is, with the SAP components relevant for warehousing functions, via a CPI-C (Common Programming Interface - Communication) interface. In this way, full integration in the overall system is ensured.

System Release Level

The R/2 host system used in conjunction with the R/3 Warehouse Management system can have Release Level 4.3 or 5.0. In this section, we refer only to Release 5.0.

For system configuration questions that are beyond the scope of this guide, please contact your SAP WM technical advisor for further information.