The size of the hardware and database is influenced by both business aspects and technological aspects. This means that the number of users using the various application components and the data load they put on the network must be taken into account.
With the help of SAP Standard Application Benchmark results at www.sap.com/benchmark, statements can be made as to CPU consumption and memory consumption of particular software components.
For sizing we have identified three different and independent sizing models that have different advantages and disadvantages. The first two, user-based sizing and throughput-based sizing, have been implemented in the Quick Sizer.
User-based sizing: We defined three types of active users who work with the system to a different degree. Merely counting the users can be done quite easily. The disadvantage is that this estimation is quite rough as it says very little about the actual throughput these users produce.
Throughput-based sizing: This model is quite thorough because it relies on actual or on actually expected throughput. However, this model relies on a number of assumptions in business terms (e.g. number of order line items per year) that need to be cross-checked against the individual installation.
Customer Performance Test: The according tests are done in a customer system with customer data. The disadvantage is that conducting these tests requires considerable time and money. For further information please refer to the white paper Carrying Out Customer Performance Tests.