Tuesday, March 19, 2013
Business user: “I can’t really say exactly when, but if we make the user wait more than a moment, they’ll just click off the site and go away.”
Architect: “Actually, if the user has to wait more than an ounce of a moment, they’ll click away and typically not return before a fortnight.”
Business user: “You’re very strange. Handsome and funny, but very strange.”
While reviewing the architecture of an online business service, we discovered that we were able to deliver the terms of a loan (interest rate, length, payments, …) in under seven seconds. This was good because our terms would then be compared to other bank’s terms side-by-side. If our terms were delivered too late, they would be ignored by the client software and we would lose the opportunity to be selected.
As it turns out, a moment is a medieval unit of time comprised of 1/40 of an hour, or 90 seconds. A moment is further comprised of 12 equal ounces, or 7.5 seconds.
I’m not sure why our medieval grandfathers needed to measure things down to the 12th of a moment, but it is interesting that hundreds of years ago we needed to express patience and urgency in elements greater than a second and less than a minute.
In the case of the aforementioned architecture (and how many times have use used the word aforementioned today?), we discovered that after a data center disaster, all of the servers needed to restore the loan term service would be recovered within a short period of time. (way less than a fortnight).
But … and this is critical..., under the “disaster recovery” environment this term lookup service would likely not deliver an answer in an ounce of a moment. In fact, the response time was likely to be over 30 seconds. A veritable ⅓ moment.
For the medieval illiterate - In a disaster recovery scenario, the loan term service would operate slower; and while still functioning, would respond so slowly that our offering would never be seen by the customer - we would be operational (technically), but essentially out of business.
Understanding how our customers experience time is and always has been an important element of staying in business. Whether we are committing to a sharper axe blade or an auto loan interest rate, we need to commit to, and deliver a rapid response. This must be true in normal business times as well as after a disaster.