Recovering hidden capacity, preparing for rate increases
A complete Assessment + Simulation Study, built in full on a modeled six-operation fabrication area so the method can be shown end to end. Everything here, from inputs to validated model to sequenced moves, is what an engagement delivers on your area.
00 · The answer
Four no-capital moves take the modeled area from missing its 90-a-day commitment on permanent overtime to meeting demand at straight time. Deliverable capacity rises 46 percent and around $1.1M a year of waste reduced. When the build rate climbs, a lean second shift carries the area to about 157 a day, counted separately.
01 · The problem
Missing demand while paying overtime
The area commits to 90 parts a day and ships about 80, missing roughly 11 percent of demand while already running 2 hours of overtime every shift. The premium is paid and the area still falls short. Before it is a cost problem, it is an on-time-delivery problem.
02 · The diagnosis
One operation caps the whole area
Every line has a drum, the one operation that sets the pace for everything else. Here the floor evidence points to Op 10, and the model confirms it, running at 100 percent while every other station shows headroom. The cart ahead of the area tells the same story, nearly two hundred parts deep and still building.
The floor also shows what a static utilization report misses. Parts visibly stack up at Op 30 even though the report reads it at about 71 percent busy, and walking the machines explains why. They are dedicated by part type, one type pool is the true limit, and parts wait about 93 minutes there while the average shows headroom. The model quantifies that wait and confirms the pool as the next constraint in line once the drum is relieved.
03 · The moves
Four moves, no capital
Four floor-level changes, not model settings. A constraint does not disappear when it is relieved, it moves, and the model predicts where it lands next. Each move was tested in the model and aimed at that next constraint before it surfaced on the floor, which is why four small moves are enough and why the sequence looks simpler than it is.
1. Relieve the drum
A processing-time study found Op 10 running each part longer than quality requires. Standard work was requalified to the shorter cycle, real work done with operators and the quality org rather than a model setting, with no loss of quality. The overtime roughly halved, and the constraint moved to Op 40.
2. Balance the line
One operator moved from Op 50, which has slack, to Op 40, the new drum. No new headcount. Overtime fell to about 30 minutes a shift, and the constraint moved to Op 30.
3. Sequence the release
A repeating, demand-mix-based release sequence keeps Op 30's type-dedicated machine pools fed without letting one part type pile up. By design it adds no throughput. It cuts WIP and lead time.
4. Root-cause the quality loss
Finding and fixing the root cause of defects cuts rework from 15 to 8 percent and scrap from 5 to 2 percent, the largest single cost cut. The last of the overtime goes, and demand is met at straight time. This is the hardest move of the four, months of disciplined root-cause work on the floor rather than a knob in the model. The model sizes what that work is worth before it starts.
04 · The result
Demand met at straight time, nothing spent
On the same crew, with no new hires and no capital, deliverable capacity rises about 46 percent. The area goes from shipping about 80 a day on permanent overtime to the full 90 a day at straight time, and it holds headroom to about 117 a day on 2 hours of overtime when demand surges. The modeled recoverable annual waste falls from about $1.4M to about $0.3M, subject to validation against a client's actual labor, material, quality, and inventory costs.
05 · The payoff
What the recovery is worth
06 · The rate path
Rate-readiness, counted separately
When the build rate climbs past what the recovered shift can hold, a lean second shift adds rate on the same equipment. Two shifts run back to back and carry the area to about 157 a day at straight time, for 4 net new hires, with 2 of the second shift's 6 operators redeployed from slack the recovery freed.
It needs no capital and no new equipment, only added labor, so it is counted separately and never summed into the recovery. The model shows each shift hitting its own drum, Op 10 on the full first shift and Op 40 on the lean second, which is what makes the two-shift day work. At each rate the model shows the labor required, the stations and machines in use, the overtime needed, and the ceiling before the next constraint binds.
What each configuration holds as the build rate climbs, from the modeled rate ramp.
| Configuration | 90/day (today) | 110/day | 120/day | 150/day |
|---|---|---|---|---|
| Current state | ~80 ceiling | ~80 ceiling | ~80 ceiling | ~80 ceiling |
| Step 1, relieve the drum | ~55 min OT | ~95 ceiling | ~95 ceiling | ~95 ceiling |
| Step 2, balance the line | ~30 min OT | ~104 ceiling | ~104 ceiling | ~104 ceiling |
| Step 3, sequence the release | ~30 min OT | ~104 ceiling | ~104 ceiling | ~104 ceiling |
| Step 4, root-cause the quality loss | no overtime | ~1.4 h OT | ~117 ceiling | ~117 ceiling |
| Rate step, two shifts | no overtime | no overtime | no overtime | no overtime |
Overtime entries are what it takes to meet that rate. Ceiling entries are the most that configuration can ship even on full overtime.
07 · The method
How an engagement runs
- The study starts on the floor. Walking the line, talking with operators, and measuring cycle times, yields, staffing, and the shift pattern. The constraint is found here, not in software.
- The line is then modeled in discrete-event simulation from its own measured inputs, and the model is validated against the line's measured behavior before any conclusion is drawn.
- Improvement moves come from floor experience. Each one is tested in the model before anything changes on the floor, so the costly decisions are made on evidence.
- The model also shows where the constraint migrates after each move, so the full sequence is known in advance and the next bottleneck is never a surprise.
- Findings land as a costed, sequenced recommendation the client's team can execute, with the evidence behind every step.
08 · The proof
How the model is validated
A model is only worth what it can prove, so this one has to earn trust twice. First against the area. The model is built from the area's own measured cycle times, yields, staffing, and shift pattern, tuned to match one measure, throughput, and then required to reproduce WIP and lead time on its own, measures it was never tuned to.
Second against itself. An accounting check confirms every part released is either shipped, scrapped, or still in process, so the model neither creates nor loses work. Every figure in the study is the average of 30 replications with a 95 percent confidence interval. In an engagement the same validation runs against the client's measured line before any future-state move is tested.
09 · The ask
The constraint is rarely the equipment
It hides in handoffs, scheduling, and flow, where no single number shows it. If your line is meeting demand on overtime, or falling behind with overtime not closing the gap, or facing a rate increase it may not hold, the locked-up capacity is likely already on your floor. I find it the same way it was found here.
This is the work the Assessment + Simulation Study delivers, a fixed fee over four weeks, on your area instead of a modeled one.
Find it on your line