Category: ReliabilityX Blog

You have three or four priced actions and a ranking by cost per hour. Now the sequence, which matters more than the list does, because the same four actions in the wrong order produce a fraction of the result. 

The sequence 

1. Stabilize. Stop the repeat failures on the constraint first. Nothing else holds while the same failure keeps returning, and every subsequent gain gets consumed by the recurrence. This is where precision skills go, because most repeat failures on rotating and reciprocating equipment trace back to how the last repair was performed. 

2. Protect. Lubrication and contamination control, so that the stability you just bought does not decay within two quarters. Skip this and you will be paying for step one again next year, on the same asset, with the same people wondering why it did not hold. 

3. Plan. Move work into planned windows. Now the gains are scheduled rather than heroic, and the constraint hours you spend are ones you chose rather than ones that chose you. 

4. Hand over. Operator ownership of the small interruptions. This scales without adding headcount, and it is the only step that keeps working after the program ends. 

Why plants start at step three 

Planning and scheduling is the most visible of the four, the easiest to purchase, and the one with the clearest deliverable. There is a system to configure, a role to fill, a schedule compliance metric to report. Progress is legible from week one. 

It is also the step that disappoints most reliably when it runs first, because planning a failure that keeps recurring simply produces a well planned recurring failure. Schedule compliance climbs, the meetings improve, and the constraint hours do not come back. 

The plants that get the result start at step one, where progress is slower and much harder to see. 

The decay problem 

Nearly every recovery effort produces results in the first quarter. A meaningful share of them are back to baseline within a year. 

That pattern is the reason your executives are skeptical of your next proposal, and their skepticism is earned. They have watched improvements arrive and leave before. From where they sit, the question is not whether your analysis is right. It is whether anything will still be true in eighteen months. 

The hours come back and stay back when three things are in place: the standard is written down, the skill is verified rather than assumed, and the result is measured on a cadence somebody owns. Remove any one of the three and the decay starts quietly, usually within two quarters, and usually without anyone noticing until the number has already gone. 

Put the hold in the funding request 

This is the practical instruction. 

Do not fund the fix and then go back later for the mechanism that holds it. Later does not come, because by then the number has decayed and your credibility with it. 

Written standards, verified skills, and a monthly view with a named owner belong inside the original request. It is a small share of program cost, it is easy to justify when you present it as protecting the investment rather than as overhead, and it is nearly impossible to add afterward. 

This week 

Rank your three priced actions by cost per hour. Then re-sequence them against stabilize, protect, plan, hand over, and see whether the ranking survives. 

Where the cheapest action is out of sequence, the sequence wins. Write one sentence explaining why the top one goes first, because that sentence is going into next week’s funding case.  

Here is the method. It is manual on purpose, it costs nothing, and it produces a number that survives an audit. Automate later if you want. Count first. 

One asset, one sheet 

A single tally sheet at the constraint. Three columns: time, duration, category. Nothing else. 

The temptation is to add fields. Shift, operator, product, root cause, work order number. Resist all of it. Every column you add lowers the completion rate, and a partially filled sheet with eight columns is worth less than a completely filled sheet with three. 

Five categories, matched to what we covered Monday: 

1. Unplanned stop or breakdown 

2. Running below rate 

3. Changeover or startup 

4. Minor stop or short interruption 

5. Quality, rework, or hold 

Count the small ones 

This is the instruction that has to be explicit, because it runs against everything the crew has been trained to do. 

Anything that interrupts flow gets a mark. Including the ninety second clear. Including the jam that one person fixed without telling anybody. Including the reach in to reposition a case that the operator has done so many times it no longer registers as an event. 

These are the ones your system has never seen, and they are the reason the counting exercise exists. If the sheet only captures what the system already captures, you have spent two weeks confirming what you knew. 

Log the rate 

Once an hour, record actual output against design. One line, one number. 

Rate loss is invisible without this, because nothing stops and nothing alarms. It is also, in a large share of plants, the second largest category on the sheet. Skipping this line is the single most common reason a counting exercise underestimates the problem. 

Reconcile weekly 

This is the step that separates a defensible number from a tally exercise, and it is the step nearly everyone skips. 

At the end of each week, total your counted hours and compare against the gap you calculated in week two. Those two numbers were derived completely independently, one from a design rate calculation and one from direct observation, so they act as a check on each other. 

If your counted hours land within roughly ten percent of your calculated gap, your number is defensible and you should stop worrying about it. 

If they do not, the difference is telling you something specific. Counted hours well below the calculated gap usually means the counting is missing a category, and it is almost always rate loss or minor stops. Counted hours well above the gap usually means the design rate is too high, or scheduled hours were overstated. 

Either way you have learned something before you present, rather than in front of the person deciding whether to fund you. 

Write your prediction first 

Before the first shift, write down what you expect to find. Which category will be largest, roughly what share. 

Then count anyway. 

The gap between the prediction and the result is where the credibility comes from. Being wrong in a documented way is far more persuasive to a skeptical executive than being right by assertion, because it demonstrates that the process produced the answer rather than confirming a position you already held. 

Two weeks, not one 

Two weeks is the minimum that spans enough changeovers, product runs, shift patterns, and crews to be representative. 

One week produces a number a skeptic can dismiss in a sentence, and they will, because dismissing it is easier than acting on it. Do not hand them the sentence.  

Everyone in your plant can describe last quarter’s big breakdown. The date, the failure, the recovery, who was called in. It generated meetings, a root cause report, and possibly a capital request. 

Almost nobody can describe the two minute stop that happens twelve times a shift, every shift, and has for two years. It has generated nothing at all, because it has never been recorded. 

On most constraint assets, the second one costs more. 

Where 1,750 hours actually go 

Our packaging line gives away $10.5mm a year. At $6,000 per constraint hour, that is 1,750 hours. Here is a representative split: 

Category	Hours	Value
Unplanned stops and breakdowns	620	$3.72mm
Running below design rate	430	$2.58mm
Changeover and startup	350	$2.10mm
Minor stops and short interruptions	260	$1.56mm
Rework, scrap, and quality holds	90	$0.54mm

Look at rows two and four. Rate loss and minor stops together are 690 hours and over $4mm, and neither one typically appears anywhere in a standard downtime report. 

Why the reporting system misses them 

Your downtime system is not broken. It was designed to explain breakdowns, and it does that competently. It was never designed to price capacity, which is a different job. 

Thresholds. Most systems only capture stops above a threshold, often ten or fifteen minutes. Everything below that is invisible by design. Twelve two minute stops per shift is twenty four minutes a shift, roughly 120 hours a year on a two shift operation, and none of it exists in your data. 

Work order dependency. Events with a work order attached get recorded well. Events cleared by the operator in ninety seconds do not generate a work order and therefore do not generate a record. 

Operator time. Coding a stop takes time the operator does not have during a run. What gets coded is what there was time to code, which biases the data toward long stops and quiet periods. 

Stale reason codes. The category list was built years ago for a different product, a different package format, or a different line configuration. Operators pick the closest available option, which is frequently other. 

Rate is never alarmed. This is the big one. A line running at 480 bags per hour against a 600 design rate is running. Product is shipping, nothing is stopped, and no alarm has fired. There is nothing in the system that treats it as a loss, and yet it is 20 percent of the asset’s capacity. 

Why this matters more than the total 

You already have a total. You calculated it two weeks ago and it is probably right. 

What you do not have is an address. A total tells you the size of the problem. A split tells you where to act, and it is the split that determines whether the money you eventually get funded actually recovers anything. 

Act on the wrong category and you will spend a real budget, generate real activity, and move the number very little. That outcome is the reason executives are skeptical of the next improvement proposal, and it is entirely avoidable. 

What you cannot outsource 

You can buy the total. Several tools, including ours, will estimate a hidden margin figure from data you already have. 

The split has to come from your asset. Every plant’s profile is different, and the difference is the entire point. If your minor stops turn out to be trivial and your changeover losses are enormous, that changes the action, the budget, and the owner. 

Two weeks of deliberate counting on one asset produces that. Nothing else does.  

The method from Wednesday is simple enough that it should work every time. It does not, and the reason has nothing to do with the method. 

The moment a tally sheet appears at an asset, the crew running that asset decides what it is. A measurement, or a performance review. That decision gets made in the first shift, mostly from tone and context rather than from anything anyone says, and it determines whether the next two weeks produce data worth having. 

If they decide it is a review, the sheet will come back clean, cooperative, and useless. Nobody will lie. The small stops will simply not get recorded, because recording them looks like documenting your own shift’s problems, and no reasonable person volunteers for that. 

Say the purpose out loud before the first shift 

Not in an email. In person, to every shift, before the first entry. 

The message is short: 

We are pricing what this asset gives away so we can go get budget to fix it. Nobody is being timed. Nothing on this sheet goes into an appraisal. If the number comes out big, that helps us, because a big number is what gets the fix funded. 

That last sentence does more work than the rest combined. It aligns the incentive. It tells the crew that thorough counting serves them, which happens to be true, because the funded outcome is fewer interruptions on their shift. 

Then prove it 

Stated intent buys you the first three days. What buys you the remaining eleven is acting on something the crew reported. 

Within the first week, take one finding from the sheet and fix it visibly. It does not need to be the biggest one. A guard that has to be removed to clear a jam, a fitting that has been leaking for a year, a tool that lives two hundred feet from where it is used. Something small, something the operator raised, fixed fast, and acknowledged as having come from them. 

One visible fix from operator reported data buys more accurate counting than any policy will. It converts the sheet from something being done to the crew into something being done with them, and the completeness of the data changes immediately. 

The single conversation that ends it 

Somewhere around day four, a manager who was not in the briefing will look at the sheet, see the number of entries, and ask why this line is stopping so many times. 

That conversation, once, in earshot, ends honest counting permanently and it cannot be repaired. The crew will conclude they were right to be suspicious, and every subsequent measurement effort at that asset will inherit the damage. 

So brief the managers, not just the crew. Everybody who might walk past that sheet needs to know what it is and what it is not. The count belongs to the asset, not to the shift. 

Give the data back 

At the end of the two weeks, show the crew the result. The ranked categories, the hours, and the dollar figure attached to the top one. 

Most people who work on a constraint asset have never been shown what an hour of it is worth. Showing them changes how the asset gets run in ways no procedure achieves, and it costs you a fifteen minute conversation at shift handover. 

It also means that when you come back in six months to count again, you will get a better sheet than you got the first time. 

This week 

Brief every shift. Brief the managers. Put the sheet out. Fix one thing they tell you about, fast and visibly. 

Then next week we take the ranked profile and start pricing what it costs to get the hours back, where some of the actions you are expecting turn out to be the most expensive hours available.  

The calculation is one multiplication. Getting the inputs right is where the value is, and where most attempts go wrong. 

The four inputs 

Design rate at the constraint. Units per hour, established as we covered last week, using the lower of the nameplate and the best documented sustained rate. 

Selling price per unit. From finance, for the product family that actually runs on this asset. 

Variable cost per unit. Also from finance. Materials, packaging, and anything else that scales with volume. 

Contribution margin per unit. Price less variable cost. 

On our line: $26.00 less $16.00 is $10.00. At 600 bags per hour, one constraint hour is worth $6,000. 

Why contribution margin and nothing else 

This is the part that decides whether your number survives its first meeting. 

Not revenue. Revenue includes the material you would have had to buy to make the extra units. Using it overstates the opportunity by a wide margin and invites an easy dismissal. 

Not gross margin. Gross margin has fixed manufacturing overhead absorbed into it. But your fixed overhead does not change when the constraint runs an additional hour. You are already paying for the building, the salaried staff, the depreciation, and the utilities base whether the hour runs or not. Deducting that overhead again from a recovered hour charges you twice for cost you have already incurred. 

Contribution margin. Price less the cost that actually varies with the unit. When the constraint produces an incremental hour of output, the full contribution margin drops through to EBITDA, because nothing in the fixed base moved. 

That last sentence is the one to have ready. It is the reason a $6,000 hour is worth $6,000 to EBITDA and not some smaller figure after allocations. 

How to run the finance conversation 

Ask for one thing: price less variable cost per unit, for the product family that runs on this asset. 

If the response is that it depends on mix, ask for a weighted average across the mix that actually runs on the line, or take the lowest margin product and use that. A conservative figure that finance provided is worth far more than an accurate figure you estimated yourself. 

Get it in writing. An email is enough. What you are doing is converting your number from an opinion into a shared assumption, and a shared assumption is almost impossible to attack six weeks later when you present. The people who skip this step are the people who spend their funding meeting arguing about the denominator instead of the decision. 

There is a secondary benefit that is worth as much as the number. Most reliability and operations leaders have never had a substantive conversation with finance about margin. This one is short, specific, and easy to say yes to, and it starts the working relationship the entire funding case depends on. 

The framework this sits inside 

Pricing the hour is step two of five. 

1. Name the hour. Identify the asset that sets the pace, because only its hours carry the full margin. 

2. Price the hour. Design rate times contribution margin. 

3. Count the missing hours. How many hours the asset did not run at rate. 

4. Buy the hours back. Rank actions by cost per hour recovered. 

5. Bank the hours. Prove the result reached the actuals, which is what gets the next one funded. 

The framework does not change. Only the asset and the numbers do, which is why it keeps working on assets you have not met yet. 

This week 

Run the multiplication. Get the email from finance. Write one line: one hour on this asset is worth this many dollars. 

Your maintenance reporting treats every hour as an hour. Two work orders closed, two hours spent, two entries in the completion rate. As a measure of activity that is accurate. As a measure of value it is badly wrong, and the error is expensive. 

The distinction 

An hour lost on the constraint is lost for the whole plant. Output does not recover, the shipment moves, and the margin on that hour is gone permanently. There is no catching it up later, because later the constraint is busy being the constraint. 

An hour lost anywhere else usually costs nothing at all. Assets with protective capacity upstream and downstream absorb the interruption. Work in process buffers it. The line delivers the same output it would have delivered anyway. 

Same labor cost, same work order, same entry in the completion rate. Radically different value. 

Most plants have been making this trade blind for years, not because anyone chose to, but because the reporting system has no field for it. 

What the constraint hour is worth 

On the packaging line, the case packer runs 600 bags per hour at design rate, and contribution margin is $10 per bag. 

600 times $10 is $6,000. 

Every hour that asset does not run at rate, for any reason at all, costs $6,000 of contribution margin. A stop costs it. A slow rate costs it. A changeover costs it. A rework pass costs it twice, once for the bad units and once for the hour spent producing them. 

The reason does not change the price. That is what makes the number so useful. 

What changes when the hour has a price 

The backlog stops being sequenced by age. Most backlogs are ordered by when the work order was raised and how loudly someone has asked. Once the constraint hour has a price, the backlog gets ordered by which asset the work protects, and that ordering can be defended to anyone who challenges it. 

The planned outage argument gets shorter. A four hour planned intervention costs $24,000 in margin. If it prevents an unplanned stop that historically runs eight hours, it protects $48,000. That is an arithmetic problem now, not a debate between operations and maintenance. 

The spare part conversation ends quickly. A $9,000 part that removes a six hour wait is protecting $36,000. Inventory arguments that used to run for months resolve in one meeting once both sides are working from the same rate. 

The overtime shift gets settled. An overtime shift that recovers five constraint hours returns $30,000 against a few thousand dollars of premium labor. Or it recovered nothing, and now you can prove that too, which is equally valuable. 

Why this is the most useful number in the plant 

Everything else in this series is built on top of it. The hidden plant figure is annual and abstract, which makes it good for getting attention and poor for making decisions. An hourly rate is operational. It works on a Tuesday afternoon, in a fifteen minute conversation, about one asset. 

It is also the number that outlives the exercise. Six weeks from now the project is over, and this figure is still sitting in your head, repricing every decision that comes past you. 

This week 

Get contribution margin per unit confirmed by finance in writing. Multiply it by the design rate of your constraint. Write it on one line. 

Then take one decision your plant made this month and reprice it. Any decision. The overtime you approved, the outage you deferred, the part you did not stock. Run it again at the real rate and see whether the answer changes.  

You now have a number: what one hour on your constraint is worth. Here is how to spend it this week. None of these require a project, a budget, or anyone’s approval. 

1. Should we take the line down for the planned work? 

This argument usually runs on instinct and organizational politics. Operations does not want the downtime. Maintenance does not want the failure. Both positions are reasonable and neither is quantified, so the loudest voice wins and the decision gets remade every month. 

Reprice it. 

A four hour planned intervention on our packaging line costs $24,000 in contribution margin. That is the cost of saying yes. 

Now the other side. Pull the history on the failure mode you are trying to prevent. If the unplanned version has historically run eight hours, it costs $48,000 each time it occurs. If it has occurred twice in the last twelve months, the expected annual exposure is $96,000. 

The comparison is now arithmetic, and it can be documented, revisited, and defended. Sometimes the answer will be to defer, and that is fine. A deferral you can justify is worth more than a shutdown you cannot. 

2. Is the spare part worth stocking? 

Inventory arguments are among the longest running and least resolvable disputes in most plants, because the two sides are measuring different things. Materials management is measuring carrying cost and working capital. Maintenance is measuring the wait. 

Price the wait. 

A critical part with a six hour lead time on a constraint asset is protecting $36,000 every time the failure occurs. A $9,000 part with a two year expected life, against a failure mode that occurs annually, is not an inventory decision at that point. It is obviously correct, and it takes one line to show. 

The reverse also applies, and you should be willing to run it. Plenty of parts sitting in stores protect assets with protective capacity, where the wait costs nothing. Pricing the hour cuts both ways, which is exactly what makes it credible when you use it in your favor. 

3. Was the overtime worth it? 

Every plant approves recovery overtime and almost none of them measure the return. 

An overtime shift that genuinely recovers five constraint hours returns $30,000 against a few thousand dollars of premium labor. That is a decision worth repeating and worth telling your plant manager about. 

An overtime shift spent on an asset that was never the constraint returns nothing, regardless of how much work got done. That is also worth knowing, and the honest version of this analysis is what makes people trust the favorable version later. 

Run last month’s overtime through the rate. Whatever the answer is, you will have learned something your plant did not previously know. 

The pattern 

All three of these are decisions your plant is already making, repeatedly, using judgment. None of them are bad decisions. They are simply unpriced, and unpriced decisions drift toward whoever argues most persistently rather than toward whatever is worth the most. 

You are not adding a process. You are adding a number to a conversation that was already happening. 

This week 

Take one real decision from your own plant this month and reprice it with your rate. Write down the before and the after. 

Bring that repriced decision into next week, because next week we stop estimating and start counting, and you will want an example of what the rate is for.  

Once you have sized your hidden plant, the first challenge you get will be about the denominator. It is a fair challenge and you should have the answer ready, because the two available answers are both correct and they serve different audiences. 

Against scheduled time 

This measures the hours you staffed, powered, and paid for. Weekends you did not run, shifts you did not staff, and planned shutdowns are excluded. 

It is the plant manager’s number. It is fair to the crew, because it only counts time the plant asked the asset to produce. It is defensible on the floor, because nobody can argue that you are charging them for hours the business chose not to schedule. And it is the right basis for the case you are going to build, because the action you will propose operates inside scheduled time. 

On our packaging line, that number is $10.5mm a year. 

Against calendar time 

This measures the asset you actually bought, all 8,760 hours of it. 

It is the capital committee’s number. It answers a different question: how much of the equipment on the balance sheet is producing margin, and how much capacity is available without buying new steel. It is the number a private equity buyer runs during diligence, and it is the number that competes directly with a capital request for additional capacity. 

It is always larger, sometimes dramatically so, and it is uncomfortable in a way that is occasionally productive. 

Why the choice matters more than the arithmetic 

Use the wrong one in the wrong room and you lose the room. 

Put the calendar time figure in front of a crew that has been working hard and you have told them, in effect, that their best week was a fraction of what it should have been. It reads as an accusation regardless of your intent, and the honest counting you are about to ask them for will not happen. 

Put the scheduled time figure in front of a capital committee that is weighing a new line and you have understated your own case, because the committee is deciding about the asset, not about the shift schedule. 

The rule is simple. Build the case on scheduled time. Keep the calendar time number in your pocket for the capital conversation, and produce it only when someone proposes buying capacity you may already own. 

The reflex this is aimed at 

When demand rises, the reflex is a capital request. New line, new packer, new building. The business case is straightforward, the approval path is well worn, and the request moves quickly because everyone involved knows how to evaluate it. 

Meanwhile the hidden plant sits inside assets already on the balance sheet. It requires no capital approval, no installation window, no ramp up curve, and no additional floor space. And it produces nothing, because nobody has sized it and therefore nobody has proposed it. 

The question worth putting in front of leadership is not whether to add capacity. It is whether to collect the capacity already purchased before purchasing more. That question has never been asked in most plants, and it is not asked because the number required to ask it does not exist. 

The objection you will get 

“We cannot sell everything we make.” 

This is the right challenge and it deserves a real answer, which is that recovered hours can be taken three ways. As volume, where they convert to margin at full value. As cost, by running fewer scheduled shifts for the same output and removing premium labor and utility hours from the base. Or as capacity held, where the hidden plant becomes a capital avoidance argument and the next line gets deferred by years. 

The mistake is treating an unsellable hour as a free one. It is not free. It was paid for. 

This week 

Calculate both numbers. Present one. Know which room you are in. 

There is a plant somewhere this month that will beat plan by three percent, hold a short celebration, and leave $10mm of contribution margin on the floor. Nobody involved will do anything wrong. 

The mechanism is the plan itself. 

How the plan absorbs the losses 

Production plans get built from history, because history is the most defensible input available to a planner. Last year’s actual output becomes this year’s baseline, adjusted for demand, mix, and known changes. Nobody would design it differently, and as a scheduling instrument it works. 

The problem is what history contains. Last year’s actuals already include last year’s unplanned stops, last year’s slow running, last year’s long changeovers, and last year’s rework. All of it is priced into the baseline as if it were a property of the asset rather than a set of losses that could be recovered. 

So the losses get inherited, and then they get hidden, because once they are inside the plan they stop being losses and start being the plan. 

Beat it and you are performing. Miss it and you are underperforming. In neither case does anyone ask the question that finds the money: what was the asset capable of? 

The two plants 

It is easier to hold if you think of it as two plants operating in the same building. 

The visible plant is what you shipped. It is measured, reported, budgeted, forecast, and rewarded. Everything about it is well governed, and it is the plant your P&L describes. 

The hidden plant is the output you already have every resource to produce and are not producing. Fully staffed, fully powered, fully supplied, fully paid for, and not collected. It has no reporting, no owner, and no line in the budget. 

The hidden margin is the money trapped in the second plant. It is contribution margin that the fixed cost base has already been paid to produce. 

That last point is what makes this an executive conversation rather than a maintenance one. You are not proposing to spend money to create capacity. You are proposing to collect capacity you have already bought. 

What it looks like in numbers 

Back to the packaging line. Case packer constraint, 600 bags per hour design rate, 417 scheduled hours in the month, $10 contribution margin per bag. 

Design output at scheduled time: 250,000 bags. 

Actual good output: 162,500 bags. 

Hidden plant: 87,500 bags per month. 

At $10 per bag, that is $875,000 a month, or $10.5mm a year, on one asset. 

Last week the same asset produced a $1.5mm figure when measured against plan. The plan was concealing a factor of seven. 

Note what this figure is measured against. Scheduled time only. It excludes weekends and unstaffed shifts entirely, which is what makes it fair to the crew and defensible on the floor. 

The word that matters is hidden 

Not lost. Not wasted. Not broken. 

Hidden means already owned and not collected, and that is a fundamentally different conversation to have with a CFO. Lost capacity sounds like an accusation. Uncollected capacity sounds like an asset, which is exactly what it is, sitting on a balance sheet you are already depreciating. 

This week 

Take your asset. Find its design rate, confirm it against the best sustained rate you have documented evidence for, and use the lower figure. Count scheduled hours for one representative month. Multiply. Subtract actual good output. Multiply the gap by contribution margin. 

Then resist the urge to soften the answer. 

This is the whole calculation. It takes longer to schedule the meeting about it than to do it. 

The four inputs 

1. Design rate. Units per hour the asset was built to produce. Start with the nameplate or the original equipment documentation. 

2. Scheduled hours. Hours in a representative month that the plant asked this asset to produce. Exclude unstaffed shifts and planned shutdowns. 

3. Actual good output. Units in that same month that were saleable. Good output, not gross output. Anything reworked or scrapped consumed a constraint hour you cannot resell. 

4. Contribution margin per unit. Price less variable cost, sourced from finance in writing. 

The arithmetic 

Design rate times scheduled hours gives design output. 

Design output less actual good output gives the hidden plant in units. 

Hidden plant units times contribution margin gives your hidden margin. 

For our packaging line: 600 bags per hour times 417 hours is 250,000 bags. Less 162,500 actual gives 87,500 bags. At $10 per bag, $875,000 a month, $10.5mm a year, one asset. 

When the design rate is a problem 

This is where most people stall, so here is how to handle each case. 

The nameplate is missing. Ask the original equipment manufacturer, who will usually have it against the serial number. Failing that, use the best sustained rate the asset has actually demonstrated, documented from a production log rather than from memory. 

The nameplate is obviously inflated. Common, particularly where the asset was specified for a different product or package format than it now runs. Use the best sustained demonstrated rate instead and note the substitution in your assumptions. 

Nobody agrees on it. Ask two people who have run the asset at its best what it does on a good day. Take the lower figure. You are not trying to win an argument about the ceiling. You are trying to establish a number that survives challenge, and the conservative version does that better. 

The principle throughout: a defensible number you can hold beats an ambitious number you have to retreat from. Every point you concede on the design rate makes the remaining figure harder to dismiss. 

Write down your assumptions as you go 

Four lines is enough. 

Design rate, and where it came from. Scheduled hours, and what you excluded. Actual good output, and whether it is good or gross. Contribution margin, and who at finance provided it. 

Those four lines are what turn your figure from an opinion into a calculation. The first person who challenges the number will challenge one of them, and having the answer ready is what ends the challenge rather than starting a debate. 

Expect it to feel too big 

It will. Nearly everyone’s first reaction to their own hidden plant figure is that it must be wrong, because a number that size would surely have been noticed. 

It has not been noticed because nothing in the reporting system was built to notice it. The P&L cannot see uncollected capacity. The plan has already absorbed the losses. OEE, where it is tracked at all, is frequently reported as a percentage without ever being converted into money. 

Do not shrink the number to make it comfortable. Test it, which is exactly what the next two weeks are for. If your counted losses land within about ten percent of your calculated gap, the number was right. 

Your twenty minutes 

Run the four inputs. Write the four assumption lines. Put the result in one sentence: this asset gives away X dollars of contribution margin per year at current performance. 

Then carry that sentence into next week, where we start finding out where the hours actually went.