"You see the whole workflow happening," he says. "You start at the end and work back toward the beginning, which is the opposite of what we usually do. And you see how everybody's tied together."

Each project's construction plan follows a now regimented time line: a three-day-per-floor cycle to erect the concrete structure, then four-day cycles for both interior rough-ins and finishes. The teams have since honed their processes to live up to that schedule, but it didn't work out that way from the start, says Tom Thrasher, a project executive on the Buckhead job, his sixth SkyHouse.

Early on, "we found that when we got to the top of the tower, we lost that cycle duration," he says. As a result, the three-day structure cycle ballooned to 10 days, and the four-day finish cycle slipped to 16 in places.

"Our productivity dropped off so much that we feel that we could've [completed construction] six to eight weeks sooner" if that first project team could've kept to the original schedule, he adds.

The culprit: Because contractors weren't completely finishing their tasks in each segment, at a later point crews were getting spread out for extensive go-back work.

Since then, Batson-Cook has worked with its subcontractors—or "trade partners," in lean parlance—to tighten down the floor-by-floor work schedule.

"We've started to implement BIM 360 and a lot of checklists to make sure we've finished all of the work on the floors as we go up, keeping the tower short, so to speak," Thrasher says.

Another key has been to further break down trade work into even smaller batches, says Tom Underwood, project executive in Raleigh.

"Each trade is in a four-day cycle to get a handful of activities done," he says, with an emphasis on repeating tasks daily.

With typically 16 units per floor, the idea is for each trade to complete its work on four units per day. Because the overall rough-in sequence is 35 days, and the finishes cycle is 50, a single trade may have multiple four-day activities.

"By doing the small batches, it helps you stay tight and develop a flow," says Rivers with Wayne J. Griffin.

Also, contractors have trimmed schedule by literally implementing the lean concept of eliminating waste. With minimal or no laydown areas at the sites, the plan is for materials to be delivered directly to the structure and installed nearly immediately. Loading the building with pallets of materials is not allowed.