I will skip the title sheet, which is merely descriptive, and start to work with the function definitions. In this case I highly recommend starting with a few key functions that are likely to provide the majority of the key performance behaviour. If this model turns out to be insufficient at a later stage then add more information as the model develops. This means that the level of detail being worked on remains manageable.
In this case I am going to use the following key functions to define the system:
- Balance Enquiry
- Create Payment
- Create Standing Order (SO)
- Approve payment
- Approve SO
- Cancel SO
- Send SO
- Send status e-mail
This set has been chosen as much to illustrate the modelling process as for their importance in a real system. There are two other major sets of information that need to be entered into the page.
The first is a “Key Function”, which is used where a particular function needs to be reported on, rather than all functions. This is used in places to simplify analysis and reporting within the model. In this case the “Create Payment” function is used.
The other information needed is the “daily usage window” for each function. This information is used during the capacity analysis, and for most functions in an internet banking system is likely to be 24 hours. For the example, however, I have limited the sending of standing orders by the system to a 3 hour batch window, with the sending of status emails to a larger 6 hour window.
Later in the modelling more detailed information will be provided.
The images shows this information entered into the spreadsheet.