What is limiting finished kits?
Alder Paper Works, a fictional paper goods shop, needs 400 accepted kits in four hours.
The question
The stages overlap. Each kit must pass all three stages during the window. The rates already allow for startup, transfers and approved checks.
| Kits per staffed hour | |
|---|---|
| Preparation | 120 |
| Assembly | 90 |
| Packing | 100 |
The opening plan staffs each stage for all four hours.
“Find what limits finished output and update the plan as the available capacity changes.”
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A strong answer, step by step
Open each step in turn. This is one strong answer, not the only one.
Step 1: Where is the constraint?
What would you do here? Open the move you’d make.
Use packing capacity because it is the final stage
Tempting, but it misses something. Packing can handle 400, but assembly can supply only 360.
Use the lowest capacity across the three stages
The strong move. Assembly has the lowest capacity in the four-hour window.
Use the average of the three rates
Tempting, but it misses something. A fast stage cannot make up for work that still has to pass through assembly.
See how a strong candidate says it
“Assembly limits output to 360 kits in four hours. That leaves the order 40 short. Prepared kits can build up before assembly.”
Why it works: A kit can finish only after all three stages have capacity for it.
Step 2: Which change helps the order?
Two changes are available. Preparation can gain 30 kits per hour, or assembly can gain 20 kits per hour. Choose one.
What would you do here? Open the move you’d make.
Raise preparation by 30 kits per hour
Tempting, but it misses something. Assembly still limits the order to 360. Extra work will wait.
Count the new assembly capacity as finished output
Tempting, but it misses something. Packing can complete only 400 in the window.
Raise assembly by 20 kits per hour and check packing
The strong move. Assembly can supply the order and packing can finish 400 with four staffed hours.
See how a strong candidate says it
“More preparation still gives 360 finished kits. The assembly change raises its capacity to 440, so packing sets the new limit at 400.”
Why it works: An improvement to the limiting stage can increase output until another stage reaches its limit.
Step 3: What changed in the plan?
The latest roster gives packing 3.5 staffed hours. Packing has enough work during those hours. The faster assembly rate remains available.
What would you do here? Open the move you’d make.
Recalculate packing capacity from the roster
The strong move. At 100 per staffed hour, 3.5 hours gives 350 finished kits.
Keep the 400 plan because the packing rate did not change
Tempting, but it misses something. That plan used half an hour the new roster does not cover.
Speed up assembly again to cover the shortfall
Tempting, but it misses something. Packing now limits finished output and already has enough work.
See how a strong candidate says it
“With 3.5 staffed hours, packing can finish 350. Even with faster assembly, the order is now 50 short.”
Why it works: Output uses the time available at each stage. The packing rate stayed the same.
Step 4: Can the team finish 400?
An approved packing bench with separate staff can complete 50 accepted kits of the same order during this window. The bench can receive its kits in time.
What would you do here? Open the move you’d make.
Split 400 distinct kits between the two packing stations
The strong move. Both stations can complete their share within the window.
Promise 440 because assembly can supply it
Tempting, but it misses something. The two packing stations can finish 400 at most.
Count 50 units already assigned to the main station again
Tempting, but it misses something. The extra bench must pack a separate set of 50 units.
See how a strong candidate says it
“I would plan 350 kits at the main packing station and 50 at the extra bench. Assembly can supply 440. The two packing stations reach 400 exactly, so I would track accepted output during the run.”
Why it works: The packing stations can work on different units at the same time. The plan has no spare packing capacity.
The answer, in short
- Decision
- Use the capacity of the limiting stage to plan accepted output.
- Because
- A change in rates or staffed hours can move the constraint.
- What would change it
- A staffing change or a lower accepted rate would change the count.
Common traps
- Check capacity in the same time window.
- Count each finished kit once.
Check your answer
- I identified the limiting stage.
- I compared both rate changes.
- I used the new staffed hours.
- I stated the available capacity and the shortfall.
Last reviewed Nov 11, 2026