In this post I will concentrate on the real scenario in which SAP projects are executed.
In our times, most of the business houses are very large and have offices, manufacturing sites, warehouses and service centers located at different parts of the world. Due to complex nature of their organization structures as well as legal requirements of local governments, it is not possible to run all of their businesses from one instance of SAP. So there will be many boxes of SAP, running at various locations and will be logically connected to each other. From performance point of view, it is also advisable to implement many boxes with each box doing some specialized work. For example, decentralized warehouses are very common so that all warehouse related work information is kept on one box dedicated to the warehouses.
On most projects, SAP MM consultants may need to work in a decentralized systems environment. Sometimes when legacy systems are not possible to be replaced with SAP then legacy systems may also be part of the landscape. Interfacing with some hardware platforms may also be required.
In such a scenario, SAP MM consultants must understand the difference between configuration of a one standalone box system to a decentralized system. I had mentioned logically connected systems in my previous paragraph. What is a logically connected system? It means that if a request for some information is sent from one system to a logically connected system, then the other system should understand the request and respond and send back information accordingly. The first system will be able to get this information.
In SAP, this exchange of information between logically connected systems is done using ALE (Application Linking Enabling). It is a kind of EDI (Electronic Data Interchange) proprietary to SAP. it is done using an electronic document with specific format so that the two system understand and exchange information without any problem. This electronic document is known as IDOC (Intermediate Document) in SAP.
From functional point of view, knowing structure and changing format of IDOCs is not required. It is job of technical consultants. However configuring the decentralized boxes is job of functional consultants. In case of decentralized landscape, definition of entities should be such that their information can be logically divided among the boxes. For example, a material can be defined on the central SAP system and later can be distributed on decentralized systems. the definition of the material on the central system should contain information which is used on that system. On the decentralized system, information related to tasks performed on that box can be kept for that material. For example, information of the material about how to store it can be kept on the decentralized warehouse system where as main material information can be kept on the central system.
When it comes to maintaining organization structure on decentralized systems, it is handled using the client and company codes.