# Cumulative cost of a few seconds

Currently, I’m on a project team that’s designing, building, and implementing call-centre software. You can probably imagine the call-centre experience from the customer side—we’ve all had our share of call-centre experiences. I’ve been looking at call centres from the other side—from the perspective of the customer-service agents and their employer.

I started by observing customer-service agents on the job. At the site I visited, the agents were using a command-line system, and the agents typed so fast that I couldn’t make sense of their on-screen actions. I signed up for several weeks of training to become a novice customer-service agent. This allowed me to make sense of my second round of observations, and appreciate how efficiently the agents handle their customer calls. It also helped me to identify tasks where design might improve user performance.

For example, after each call the agent decides why the customer called, and then, by scanning lists of main reasons and detailed reasons, “wraps up” the call, as illustrated. I measured the time on task; the average wrap-up task is nine seconds in duration.

It’s only nine seconds

Nine seconds may not seem long, but let’s make a few (fictitious but reasonable) assumptions, and then do a little math.

If the average call-handling time is five minutes, or 300 seconds, the 9 seconds spent on call wrap-up is 3% of the total handling time. A full-time agent could spend 202,500 seconds—that’s 56¼ hours per year—on call wrap-ups, assuming a 7½-hour workweek and no lulls in incoming calls. Since call volumes vary, there will be times when call volumes are too low to keep all agents taking calls. The customer-service agents have other tasks to complete during such lulls, but if we assume this happens about a third of the time, we need to round down the 56¼ hours accordingly. Let’s choose a convenient number: 40 hours, or one workweek per agent per year.

One workweek is 2% of the year.

Based on this number, a redesigned call wrap-up that takes only half the time would save one percent of the labour. Eliminating the wrap-up entirely would save two percent. That frees a lot of hours for other tasks.

A similar calculation on the cost side (n hours to design and implement changes) leaves us with a simple subtraction. Projected saving minus cost is the return on investment, or ROI. Comparing that number to similar numbers from other projects that we could tackle instead—the opportunity costs—makes it easy to decide which design problem to tackle.