Case Study 8-2 — The Five-Day Cycle That Ran Eight

Ray's own failure, fourteen years ago, on a cast-in-place concrete frame. Four causes, none of them dramatic, all of them compounding — and roughly half a job's profit.

All parties, projects, and figures here are Tier-3 illustrative composites.

Setup

The project. The Cortland Street Apartments — 190,000 gross square feet, twelve typical residential floors of cast-in-place flat-plate concrete over a two-level parking podium, in Rivermont. Lump-sum contract, private developer, 480 calendar days. Liquidated damages $3,500 per calendar day. Kestrel's extended general-conditions rate on that job was $4,200 per calendar day. Budgeted profit at buyout: $1,340,000.

The people. Ray Alvarez, then in his second job as a project manager. Jamal Foster, concrete superintendent — the same Jamal who runs Kestrel's self-perform crews on Northgate today. A formwork subcontractor supplying flying table forms and shoring, and Kestrel's own carpenter and rodbuster crews doing the placing.

The plan. One floor per 5 work days. Twelve typical floors, therefore 60 work days of frame, five days a week. The schedule bar in the CPM read "Levels 3–14 structural frame — 60 wd."

The cycle, as drawn on a whiteboard in the trailer:

   Day 1        Day 2        Day 3        Day 4        Day 5
  +----------+ +----------+ +----------+ +----------+ +----------+
  | STRIP &  | | SET      | | BOTTOM   | | TOP      | | PLACE,   |
  | FLY forms| | forms,   | | rebar,   | | rebar,   | | FINISH,  |
  | up 1 lvl | | screeds, | | MEP      | | embeds,  | | CURE     |
  | RESHORE  | | edge     | | sleeves, | | INSPECT  | |          |
  | below    | | forms    | | conduit  | | (hold)   | |          |
  +----------+ +----------+ +----------+ +----------+ +----------+

What actually happened. The cycle ran 8 work days, every floor, from Level 4 onward. Not once. Twelve times.

What Happens

Level 3 took nine days and everyone called it a learning curve. Level 4 took eight. Level 5 took eight. By Level 6, Ray was in the trailer at 6:40 a.m. with a legal pad, and Jamal was already there.

Jamal: "You want the honest version or the version for the report?"

Ray: "Honest."

Jamal: "There is no five-day cycle. There never was. Somebody drew a bar. Nobody counted carpenters."

The compounding arithmetic

12 floors × 3 extra work days = 36 extra work days

36 work days ÷ 5 work days per week = 7.2 weeks = ~50 calendar days

Fifty calendar days on a job whose entire float had been consumed by a wet spring during the podium.

Budgeted profit $1,340,000. Actual profit at closeout: $628,200. Ray's job gave back 53% of its profit to three days a floor.

The Four Causes

Jamal and Ray reconstructed it over two weeks, with the daily reports and the crane logs on the table. There was no single villain.

Cause 1 — The cycle was never planned as a cycle

The CPM had one bar: Levels 3–14 structural frame, 60 wd. Nobody had decomposed it into the five activities, assigned a crew to each, computed the carpenter-hours a 5-day cycle demanded, and compared that to the carpenters actually on the job.

When they finally did the arithmetic, the answer was ugly. The deck area required roughly 1,150 carpenter-hours per floor for form, set, and strip. A 5-day cycle at 9 hours per day gives 45 hours per carpenter per cycle. That is 1,150 ÷ 45 = 26 carpenters. Jamal had 17.

17 carpenters × 45 hr = 765 carpenter-hours per 5-day cycle, against 1,150 required

1,150 ÷ 765 = 1.50 → a 5-day cycle stretches to 7.5 days on labor alone

The schedule was not aggressive. It was arithmetically impossible, and a fifteen-minute calculation would have said so before the first floor.

Cause 2 — Not enough formwork, and no early-strip strength analysis

The buyout carried two sets of flying forms and three levels of shoring and reshoring. A 5-day cycle with two sets requires stripping and flying a deck on day 1 of the next cycle — which means stripping at roughly 4 days of age.

Nobody had asked Caldwell Structural, the engineer, what strength was required for early stripping and what the reshore analysis permitted. When the question finally got asked, in writing, on Level 6, the answer came back requiring a higher percentage of f′c before stripping than the crew had been assuming, and cylinder results were not consistently there at four days. So the forms sat an extra day, sometimes two.

ACI 347 addresses formwork, including the removal and reshoring questions, and the specification referenced it. Nobody had read that part either.

Cause 3 — Embed and sleeve coordination happened on the deck

Three subcontractors — plumbing, electrical, and fire protection — issued sleeve and embed layouts on three separate drawings at three different times. Nobody overlaid them. So the coordination happened at 2 p.m. on rebar day, on the deck, between two foremen and a tape measure, with a rodbuster crew standing by.

On Level 7 the electrician and the plumber spent four hours resolving a six-inch conflict at a shaft wall. On Level 9 an RFI went out at 3:40 p.m. asking whether a 10-inch sleeve could move 14 inches; the answer arrived the following afternoon. Each of those is half a day to a day, and it happened on most floors.

📊 What the fix looks like. One overlay drawing per floor, produced by a field engineer three cycles ahead, signed by all three subcontractors, with conflicts resolved in the office. On Northgate today, Grace Lindqvist does this in the model and it takes an afternoon — see Chapter 35. In year one of that job, the same work by hand on a light table would still have saved eight days.

Cause 4 — Inspection and testing were not activities in the cycle

The rebar and embed inspection on day 4 was a hold point. It was not in the cycle as an activity with a duration, a responsible party, and a notice requirement. The superintendent called the special inspector when the deck looked ready — usually mid-afternoon on day 4. The inspector arrived the next morning about half the time.

That alone is roughly 0.5 days per floor, six days over twelve floors. The fix cost nothing: put the inspection on the look-ahead as an activity, give the inspector a standing 24-hour advance notice off the schedule, and confirm the day before.

Analysis

Why it compounded

Three days a floor did not stay three days a floor. As the cycle stretched, three second-order effects arrived.

1. The crane became the constraint. The tower crane had been sized and scheduled for a 5-day cycle, with hoisting capacity allocated between the frame and everything else. On an 8-day cycle, the frame occupied the crane for the same total hours but spread across 60% more calendar time — and the curtain wall, the masonry at the podium, and the MEP risers all queued behind it. By Level 10 the crane was booked from 6:30 a.m. to 5:00 p.m. with a waiting list.
2. The trades behind the frame inherited every day. Enclosure, MEP rough-in, and drywall each start a fixed number of floors below the working deck. Slipping the frame slips all of them, and none of them can compress without adding crews to a building that is already crowded — which is how you get trade stacking.
3. Acceleration was bought late and therefore expensive. By the time Ray accelerated at Level 8, he was buying premium time in a hot market with no leverage. Acceleration bought at Level 3 would have cost a fraction.

The pattern, stated generally

A cycle is a production system, and a production system fails at its slowest station. The frame at Cortland Street had five stations. Two of them — carpenter-hours and inspection notice — were under-resourced, and one — embed coordination — was performed at the wrong time and place. None of the three was dramatic. Each cost roughly a day. Three days a floor, twelve floors, half the profit.

This is theme 3 in its most expensive form. The project is built twice. The Cortland Street frame was built the first time in a schedule bar that said "60 wd" and had never been tested against a crew list, a formwork inventory, a strength requirement, or an inspector's calendar. It took twenty minutes to fix on paper and $711,800 not to.

And it is theme 2 as well: the schedule and the budget are the same conversation. Ray had a cost report showing concrete labor over budget from Level 4 onward, and a schedule showing the frame slipping. Two reports, two meetings, two audiences. Nobody put them on the same page until Level 6.

Jamal, at the closeout lessons-learned meeting: "The cycle tells you the truth in the first two floors. After that you're just watching it happen."

Discussion Questions

1. Of the four causes, which one is cheapest to fix, and which one is most likely to recur on your next project? Are they the same cause?
2. The carpenter-hour calculation — 1,150 hours per floor against 765 available — took fifteen minutes. Why do you think nobody performed it during buyout? What in the estimating and scheduling handoff process allows a bar labeled "60 wd" to exist without a resource check behind it?
3. Ray accelerated at Level 8. Argue the case for accelerating at Level 4 instead, including what he would have had to tell the developer and what he would have had to admit.
4. Compare the failure here to the Northgate steel delay: six days in an office becoming twenty-three calendar days. Both are schedule failures with a paper cause. What is structurally different about them, and does that difference change how you would defend against each?
5. The crew inefficiency line is $128,800 based on a 40% loss factor. That factor is a judgment, not a measurement. How would you have documented crew productivity contemporaneously so the number was defensible? What would you have needed to start collecting on Level 3? (See Chapter 26.)

Your Turn

Take any repetitive construction cycle you can observe or find documented — a concrete floor cycle, a residential production schedule like Harbor Ridge's 92-calendar-day house cycle, a hotel guest-room finish sequence, a highway paving pass.

1. Decompose it into its stations. Name each one, and name the crew that performs it.
2. For the two stations you believe are most constrained, compute the required labor-hours and compare them to the labor-hours actually available in the cycle duration. Use the Cortland Street arithmetic: required hours ÷ (crew size × hours per cycle).
3. Identify every hold point in the cycle — inspection, test result, strength gain, submittal approval — and write down who controls the notice.
4. State the cycle duration your arithmetic supports, and compare it to the cycle duration in the published schedule.

If those two numbers disagree, you have found the most valuable thing on the job that week. Write down the difference, multiply it by the number of cycles, and take it to whoever owns the schedule. That is the entire job, in one exercise.