When implementing SAP software, three infrastructure technologies come into play:

Hardware
Operating System
Databases

Hardware, operating System, and databases are underlying technologies or foundations for SAP business software solution.

A week foundation could weaken the whole SAP system sitting on top of the foundation.

These layers are also called solution stack or technology stack.

Do not make your hardware, OS, and database selection based on what your company is already familiar with, within the context of desktop applications.

Choosing an SAP infrastructure partner is a serious business.

First get a sense of what you might be already comfortable with.

Then investigate other prospective infrastructure providers.

Factors you need to look at are:

• What kind of relationship the vendor has with SAP?
• Do they have a long history of partnering with SAP?
• Are they certified SAP partners.
• Do they possess SAP's Global Technology Partner" status?

Also you should consider:

• Checking references by contacting existing SAP customers
• Attending SAP trade-shows. For example SAP TechED, ASUG, SAP Insder conferences