What is meant by 'valid and invalid advances' in the context of the ATM upgrade project?

In the context of an ATM upgrade project, 'valid and invalid advances' typically refers to the range of cash amounts that customers can withdraw. Valid advances would represent the permissible withdrawal amounts that the ATM can dispense, based on account balance, withdrawal limits, and operational status. For instance, valid amounts might be those that are in increments defined by the bank, while invalid advances would cover amounts attempted by customers that exceed their account limits or are not dispensed by the ATM due to machine restrictions.

Understanding valid and invalid cash advances is critical for ensuring the ATM functions correctly and meets customer expectations. It also plays a role in testing the ATM system to ensure that it accurately recognizes and processes valid withdrawal amounts while properly rejecting invalid ones. This is crucial for maintaining the integrity of transactions and preventing errors or fraud in cash dispensing.