Twelve-Hour Shifts at the Axbury Water Plant

Resolution: The Axbury water treatment plant should move from three eight-hour shifts a day to two twelve-hour shifts.

Background. Axbury is a fictional city of about 40,000 people. Its treatment plant is staffed every hour of the year. Right now the day is split into three eight-hour shifts. Each shift ends with a handoff, when the operator leaving tells the operator arriving what happened.

Under the proposed schedule, the day would be split into two twelve-hour shifts. Operators would work fewer days and would hand off twice a day instead of three times. Every detail about Axbury in this kit was invented for the debate.

Operators at the plant watch turbidity, which is a measure of cloudiness in the water. Conventional filtration plants must keep finished-water turbidity at or below 0.3 NTU in 95 percent of monthly samples, and never above 1 NTU. When a filter starts to drift, the operator on duty decides whether to backwash it, slow the plant down, or call the supervisor.

Roles. Two teams of three or four argue the affirmative and negative sides. One student moderates and keeps time. Three or four students sit as the plant's labor and management committee and score with the rubric. Each team prepares a two-minute opening, one rebuttal, and a one-minute closing.

Case for twelve-hour shifts

1. Fewer handoffs mean fewer dropped details. Under the current schedule the fictional Axbury plant hands off three times a day. Two twelve-hour shifts would cut that to two. Every handoff is a place where a note can be missed. (Illustrative argument written for this debate.)
2. The plant's own log supports that point. In our scenario, the supervisor reviewed six months of logs and found that most missed follow-up items appeared right after a shift change. (Illustrative figure created for this debate.)
3. Operators gain whole days off. Twelve-hour shifts can be scheduled, with four crews rotating, so each operator works seven days in a two-week period. Fictional Axbury operators who drive 30 minutes each way would make far fewer trips. (Illustrative argument written for this debate.)
4. Coverage gets simpler. When one operator calls out sick, the supervisor has to fill one long slot rather than find pieces of three. A fictional shift lead at the plant said the daily puzzle of coverage takes an hour of her morning. (Illustrative testimony written for this debate.)

Case against twelve-hour shifts

1. Attention fades late in a long shift. A filter that drifts toward the 0.3 NTU figure at hour eleven still needs a clear decision. The operator has to choose whether to backwash, slow the plant, or call for help. (Source: EPA Surface Water Treatment Rules for the turbidity figure; the rest is an illustrative argument.)
2. A long day is not equally workable for everyone. A fictional Axbury operator with young children told the committee that a twelve-hour day would cost him childcare he cannot arrange. Two other operators asked for the change. The committee heard both views from people doing the same job. (Illustrative testimony written for this debate.)
3. Overtime gets more expensive. Under the proposal, anyone covering an extra shift covers twelve hours rather than eight. In our scenario the plant paid $31,000 in overtime last year, and the finance director expects that figure to rise. (Illustrative figures created for this debate.)
4. Training time gets squeezed. The fictional Axbury plant runs its operator training during the overlap between shifts. With one fewer overlap each day, there is one fewer window to train the newest operator. (Illustrative argument written for this debate.)