NetWeaver architecture concepts - need clarification

[Former Member]

Hi

I'm relatively new to SAP and trying to wrap my head around some of the concepts from an IT perspective. I'm a developer myself, but like to know how everything hangs together for a bit more depth of knowledge.

Please could someone explain the following concepts to me?

1. How is a SAP system defined? I originally thought this was a fully encapsulated system that could potentially include all relevant components (e.g. ERP, CRM, etc.) that were required. But then I found that CRM is actually installed as a separate system. This has thrown me off a bit. What exactly is a SAP system?

2. What is a Dialog Instance? What is the purpose of it? Is it purely for load balancing requests across multiple servers (either virtual or physical)?

3. Do all Dialog Instances have to be the same within a system? For example, if you have 3 dialog instances (each on their own physical server), must they all have the same software components installed (e.g. Portal, etc.)?

Any general guidance to understanding the architecture of NetWeaver would be greatly appreciated!

I have searched for answers to this in the forum, but didn't find anything suitable. Apologies if this has already been asked.

Thanks

Stuart

[Former Member · Accepted solution]

Hi,

>What exactly is a SAP system?

If you don't tell which kind of SAP system it is, it does not mean a lot.

This may be : R/3 or ECC or PI or EP or CRM or SRM or MDM !

The SAP company used to be nearly a single product software vendor (R/2 then R/3). Nowadays there are plenty of functional software which may be using for each one several technical systems.

For example, we have a Supplier Relationship project. This project uses all these SAP systems : SRM, R/3, XI and MDM-catalog.

>2. What is a Dialog Instance? What is the purpose of it? Is it purely for load >balancing requests across multiple servers (either virtual or physical)?

Yes, you are right. a Dialog instance is just an application server for the abap stack. When you have several of them in the same technical system, you can use load balancing.

>3. Do all Dialog Instances have to be the same within a system? For example, if >you have 3 dialog instances (each on their own physical server), must they all >have the same software components installed (e.g. Portal, etc.)?

A dialog instance is just : kernel executables and shared memory. All the software components are centrally located in the database. The kernel patch level must be the same for all the dialog instances of the same system.

Hope this helps.

Olivier

[Former Member · Accepted solution]

Thanks Olivier

Your answers were very helpful!

Regarding your answer to my first question:

Some of those components may be set up in their own system, or included together in a single system (e.g. ERP and EP). So if these can be components of a system, then they are not what defines it as a whole. What I'm battling to understand is why a company must have separate SAP systems? For example, ERP & CRM are separate systems. Surely these overlap at some point? Are you forced to use something like MDM to keep the common data aligned, or is this managed in some other way? Why the added complexity?

I'm asking purely to get a better understanding of how it works. It seems few people really know the answers, so I'd like to find out for myself.

[Former Member · Accepted solution]

Hi Stuart,

>

> Some of those components may be set up in their own system, or included together in a single system (e.g. ERP and EP). So if these can be components of a system, then they are not what defines it as a whole. What I'm battling to understand is why a company must have separate SAP systems? For example, ERP & CRM are separate systems. Surely these overlap at some point? Are you forced to use something like MDM to keep the common data aligned, or is this managed in some other way? Why the added complexity?

>

The technical SAP architecture is very complex and there is usually no definitive answser. Each case has to studied for the specific need of a specific company.

Some components can be installed in the same system when the technical base is the same.

For exemple, you can activate BI 7.0 in an ECC 6.0 system because both are based on Netweaver 7.0.

But it is usually a very bad idea for a production system because one system is using the database in OLAP mode (BI) and the other one in OLTP mode.

In BI you may want want to use the integrated portal EP to publish some queries but if you already have an independent enteprise portal EP, it would make more sens to use it.

ERP and CRM overlap on some functionalities, it is a company choice to use ERP or CRM for a specific common functionality.

The added complexity is what gives you more flexibility...

But I can tell you that, some times, I regret the good ol'days where all was in one single R/3 system. Life was much simpler for architects !

Regards,

Olivier