HDFC’s faster ATMs

40% faster ATMs on television and posters. As a performance tester, , so I observed these advertisements predominantly displayed at the Bank’s ATMs. The other day while going for office, I saw a big hoarding mentioning that HDFC’s ATMS are 40% faster now. There was a sentence below that in a smaller font : Choose your MyFavourite option today.

More details of the same are available at the HDFC website.

Analysis

(the figures are mentioned in the Indian context. Money values are in Rupees):

In the subject of performance engineering, there are known principles and patterns. Following are the related ones to this advertisement:

Centering Principle: Focus attention on the performance of the scenarios that are exercised the most or have large performance impact.

Fast Path Pattern: To cater to the centering principle, one way is to provide an alternative execution path which minimizes the steps of execution or dedicates more resources than other scenarios.

Withdrawl is definitely one of the transactions which fits to the centering principle crtietria. Interestingly, there are already hardcoded fast paths available in ATM’s e.g. “Withdraw Rs1000/-”, “Withdraw 4000/-” etc. These are based on study of transcations commited by the customers over a period of time and observing what are the most common values of money withdrawn. There is a limit to providing such hard-coded fast paths, so I guess someone suggested HDFC to come up with a “MyFaviourite” option. This is a sort of “customised fast path” for a customer wherein the customer would make a transaction and then save the same as a favourite. As per my analysis, following is how performance benefits are realized (or not):

1. For the first time, no performance improvements are observed. This is because there are no inherent performance improvements in the time taken by the withdrawal logic. Only instead of multiple steps – choose withdraw / enter amount/ confirm, only one step would exist whereby customer chooses his/her favorite amount for withdrawal. Also, time taken to choose and amount rather than entering the amount digit by digit and clicking OK, is much faster.
2. With a non-HDFC card, you can not choose this option. Understandably, the favourite option should be stored on the server side and not on the ATM machine (as settings shouldn’t be ATM machine specific rather than account specific). HDFC would store data only for HDFC cards on the server side. (I am not sure whether at a later stage when more banks open this option, this could be got via web-services.).
3. On same lines, this wouldn’t work with HDFC card on a different bank’s ATM machine
4. Next time, when the customer withdraws money, 40% performance improvement (as claimed) would be observed.
5. The performance improvement is observed only if the transaction is made for the same amount, which was saved as a MyFavourite option
6. You can not store > 10000 as a MyFavourite option, because of the recent RB rulings of withdrwal of only a max of 10000/- per transaction.
7. Only one favourite option can be chosen at a time. This means that only those will get the performance benefit who tailor their withdrawl habits and confine it to a single type of amount withdrawl (or choose it carefully with respect to already existing ones).
8. Choosing a favourite withdrawl option of say Rs 1000/- which is already provided as a fast path, is redundant.
9. “40% faster performance” is based on averages of data collected by HDFC on transaction times from the ATMs. So, the experience would differ from one customer to other

In the light of the above, HDFC’s ATMs are probably working at the same speed. It’s not the ATMs which have become 40% faster. This statement indicates that whatever operations one was doing earlier would take 0.40x less time, but that’s not the case. The improvement is confined to withdrawl transaction for a specific chosen amount (only if configured prior to the transaction).

So, have they done a bad job? No, not at all! Providing a customized withdrawal fast path is a very good idea and will serve many a customers in a good way. Thinking of providing this is definitely a step in the right direction.