Bottleneck Theory Model

Your instinct is correct — adding a second shift to the CNC without re-examining the system is classic "elevate before exploit," and it usually fails. The bottleneck rarely moves just because you threw more capacity at it; more often, you've simply created a bigger queue in front of the next constraint.

Run the Five Focusing Steps in order. First, identify — is the CNC truly the constraint? Measure its utilization against the sanding and assembly lines over a full week, not a day. If sanding is idle 50% of the time, but the CNC is producing parts that sanding can't process fast enough, then the real constraint is downstream. Second, exploit — before adding shifts, ensure the CNC never stops for setups, breakdowns, or missing materials. Third, subordinate — make sanding and assembly's pace match the CNC's output, not the other way around. Fourth, only then elevate.

If output barely moved after the second shift, you're likely feeding the wrong link. The bottleneck has probably shifted — look for the operation where work-in-process piles up after the CNC. That's your new drum. Stop the second shift until you've confirmed the constraint, or you're just burning labor to build inventory.

Stop treating symptoms. You've jumped to "exploit" without "identify." The pharmacy, transport, lab — none of them is your constraint until you measure flow, not activity. Walk the actual discharge path and time every step from the physician's discharge order to the bed being cleaned and flagged ready. The constraint is the step where work-in-process piles up — where patients wait the longest relative to capacity. That's your Herbie. It could be the transport team holding stretchers, the lab batch-processing results, or even the bed-cleaning crew working only during day shifts. Don't assume. Collect shift-level data for one week: timestamps for order, med delivery, transport request, lab result, and bed ready. The step with the longest average wait and the highest queue is your drum. Once you find it, exploit it — never let it idle. If transport is the constraint, pre-schedule pickups and hold patients at the floor, not the lobby. Subordinate pharmacy and lab to that beat: they produce when transport calls, not before. Only after that, consider elevating — more transport staff or a second shift. And remember: the moment you fix transport, the bottleneck will move. Re-identify before you invest in anything else. Measure flow, not effort.

Identify the True Constraint

Your packing machine is a non-constraint—it has excess capacity. The conveyor jams are a symptom, not the cause. Apply Step 1: identify the system's constraint. Measure where work actually accumulates. If orders pile up before the conveyor, the constraint is upstream (picking or release). If they pile up after, it's the conveyor itself. Don't guess—track WIP at each point.

Exploit Before You Elevate

Stop adding resources. Step 2 says exploit the constraint. If the conveyor is the bottleneck, run it at full capacity, schedule maintenance off-peak, and never let it idle. If picking is the constraint, then the conveyor is fine—your 180 machine is irrelevant until picking improves. Subordinate everything: the packing machine must wait, not push.

The Real Test

Run a 2-hour experiment. Freeze upstream input, then watch where orders stop moving. That's your constraint. If it's the conveyor, fix jams mechanically—not by buying more machines. If it's upstream, your conveyor was masking it. Either way, you've broken the illusion of the 180 number. Throughput is set by the weakest link, not the fastest.