-Looking at the requirements, and knowing that we have only two - -2
-that we can satisfy for sure, it makes sense to first mark - -3
-as mandatory the ability to withdraw cash, which is the most typical - -4
-use of an ATM machine. We are therefore going to mark this requirement - -5
-with an M, for mandatory. It also makes sense to mark as - -6
-mandatory the fact that the ATM system checks the PIN of the - -7
-card being used by the customer, as that's the typical level of - -8
-security that the customer would expect, - -9
-therefore we're going to mark as mandatory - -10
-also the first requirement here. And of course we - -11
-could also perform biometric verification, but based on our knowledge - -12
-of the domain, it seems like that should be - -13
-an additional verification, rather than the main and only verification - -14
-for the system. We will therefore mark it superfluous. - -15
-That is something that we can postpone until a later - -16
-release, the second requirement. Finally, - -17
-another typical operation that customers - -18
-perform at ATM machines is depositing. Whereas changing an ATM - -19
-card's PIN is not such a common operation. We'll therefore mark - -20
-it nice to have this fourth requirement and as superfluous, the - -21
-last one. So at the end, what we have is that - -22
-we have two mandatory requirements which are the two that we can - -23
-satisfy for sure. One, nice to have the requirement, which is - -24
-the possible third requirement which we might have time to satisfy. And - -25
-the other two that are marked as superfluous, as something that - -26
-we might do later, for example in a subsequent release. And of - -27
-course there is something subjective in these answers. But - -28
-again, based on our knowledge on our understanding of - -29
-the domain, these are the one that makes more - -30
-sense for an ATM system as we know it. -- cgit 1.4.1