A second filler looks like the obvious answer when a line cannot keep up. It is also one of the most expensive ways to discover that the filler was never the constraint. If the real limit sits at the capper, the cooling tunnel or the case packer, new filling capacity simply moves the queue downstream and the capex earns nothing. A bottleneck elevation ROI calculator starts by proving where the constraint is, then prices every option against the output it would truly unlock. Plant teams can run a capex case against their own line data before approval and see what it really returns.
Prove the Constraint First, Then Spend the Capex
iFactory bottleneck analysis checks whether a machine is the constraint, then calculates what elevating it is actually worth.
Prove Then Spend: The Order of the Calculation
The calculation only works in sequence. Skipping a step is how capex lands on the wrong machine.
What Happens When You Elevate the Wrong Machine
Output is capped by the slowest step. Raise a machine that is not the constraint and the cap simply stays where it was.
Illustrative capacities. Upgrading the filler would not move the cap.
The Inputs a Credible Calculator Needs
Use measured values. Each input has a natural source in the plant.
| Input | What to Capture | Where to Find It |
|---|---|---|
| Constraint capacity | Rate and demonstrated output | Line records |
| Demand beyond capacity | Orders lost or delayed | Sales and planning |
| Contribution per unit | Margin on extra output | Finance |
| Option costs | Capex, installation and downtime | Supplier quotes |
| Operating costs | Labor, utilities and maintenance | Plant budgets |
Cheaper Fixes to Test Before Buying Capacity
Many constraints can be relieved without capital. Rank these against the capex option.
Illustrative relative potential. Your own constraint data sets the real ranking.
Check Whether Your Next Machine Is Worth Buying
Bring a proposed capex and one month of line data. We will test whether it is the constraint and calculate the return.
Three Outcomes a Good Calculator Reveals
The answer is not always yes or no.
Elevate now
The constraint is proven and the payback is clear
Exploit first
Cheaper fixes release enough capacity to delay capex
Look elsewhere
The machine is not the constraint, so the money belongs somewhere else
Capex-First vs Proof-First
Both aim for more output. One protects the budget while it gets there.
Reading the Calculator Output
A good calculator ends in a few numbers anyone can challenge.
Hidden Costs Capex Cases Often Forget
The purchase price is rarely the whole bill.
Installation downtime
Lost production while the machine is installed and commissioned
Extra staffing
People needed to run and feed the added capacity
Utilities and consumables
Power, air, water and spares for the new machine
The next bottleneck
A downstream machine that now caps the gain
A Staged Approval Path
Releasing money in stages limits risk while evidence grows.
Questions Finance Will Ask
Prepare data for these questions before the meeting.
| Question | Evidence Needed | Who Owns It |
|---|---|---|
| Is the machine the constraint? | Queues, starvation and output data | Operations |
| Can demand absorb extra output? | Order book and forecast | Sales |
| What margin does extra output earn? | Contribution per unit | Finance |
| What could go wrong? | Risks and sensitivity results | Engineering |
Common Sources of Overestimated Benefit
Cases fail on optimistic inputs more often than on arithmetic.
Illustrative frequency of error types. Your own review shows where cases slip.
What Experienced Finance and Operations Leaders Check
Frequently Asked Questions
How do we prove a machine is the bottleneck?
Look at where work waits, which machines starve and what happens to output when that machine changes. Speed alone is not proof. A simple test is to ask what would happen to line output if the machine ran faster, and the data should show whether the next machine would then limit it. Include a simple record of queue levels and starvation events from a few typical weeks, so the evidence does not rest on a single good or bad day. Test your suspected bottleneck against a month of line data with our team.
What if the new capacity just moves the bottleneck?
It often does, which is why the calculator checks the next constraint. The gain is limited by that next machine, and the case should show it. That is why the case should list the next two likely constraints and show the output ceiling after each, so the true gain is not overstated. When the next constraint is close in capacity, the case may favor a combined upgrade, and the calculator can show whether paying for both still returns the money.
Should we include cheaper improvements in the case?
Yes. Showing alternatives makes the capex case stronger or avoids it. Cheaper fixes often release capacity faster and with less risk, and they may reduce the size of the capital request or remove the need for it. Document each alternative with its cost, expected gain and time to implement, so reviewers can see why the chosen route was picked over the others. Compare exploit options with elevation for your line in a working session.
How accurate is the payback figure?
Accuracy depends on demand, margin and demonstrated capacity inputs. Sensitivity checks show which assumption matters most, so the decision can rest on a range, not a single number. Present the result as a range with a clear note of the most uncertain input, because decision makers trust a range with reasons more than a single precise number. Sensitivity checks on price, volume and ramp-up time show how far each input can move before the payback stops being acceptable.
Who should be in the room for the decision?
Operations, finance and sales together. Each owns an input. Having all three groups present also avoids late surprises, since a gap in demand evidence or cost data is found before approval and not after purchase. A short pre-read with the key data and the main question helps the meeting focus on the decision and not on collecting numbers. Plan which data each group should bring on a short call.
Put Capex Where the Constraint Really Is
Bring your capex proposal and line records. We will show whether it is the constraint and what the money would return.
