Sizing Theory and Practice

SAP sizing is based on a theoretical concept called the queuing model (or queuing theory). In this kind of modeling the queuing systems are studied mathematically to estimate the performance criteria such as response times. A SAP three-tiered software architecture is studied as a queuing model with one service center (CPU). In this three-tiered SAP architecture, all the major system resources, such as memory, disk, and network load, can be spread out in such a way that any queuing can be significantly reduced. However, the CPU of the database server is the single most-limiting factor in a three-tiered SAP software architecture and is, therefore, looked at first as being responsible for any major queues, which could cause delays in system r....