This page explains how to calculate a new machine's payback period: the months it takes for what the machine saves to add up to what it cost. This matters to a production manager comparing a supplier's quote against a factory's budget, a factory owner deciding whether a machine is worth buying, and a merchandiser explaining a delivery decision that depends on a machine not yet installed.
Delta Garments, the export garment factory used throughout this lesson, runs Make to Order production for its export buyers. Karim, its production manager, has just received a supplier's quote for a machine that promises to save labour time and reduce stoppages on the sewing floor. Ownership wants to know whether the machine "pays for itself," and Karim needs a real answer, not a feeling.
Without this skill, a manager either guesses at a payback period, or types one division result into a spreadsheet and never checks it again. Both leave a factory guessing whether a machine investment makes sense, and both go silently wrong once the machine's real price or saving differs from the supplier's first estimate. This lesson gives you the rule and the formula-driven habit that keeps a payback calculation correct after the numbers change.
You need: no previous Track 8 lesson, though it helps to already know how a factory's sewing floor is organised (Course 8.4) and how machine choice affects output (Course 8.5).
By the end of this lesson you can:
Not covered here: comparing preventive and breakdown maintenance cost for a machine already owned (lesson 6.2), building a full maintenance schedule and tracking its running cost (lesson 6.3), and combining a payback calculation with an old machine's rising maintenance cost to decide whether to replace it (lesson 6.4).
| Term | Meaning |
|---|---|
| Payback period | The time it takes for a machine's total monthly savings to add up to its total investment cost. |
| Depreciation | Spreading a machine's purchase cost over its useful working life instead of counting it all in the year it was bought. |
| Preventive maintenance | Scheduled inspection and parts replacement done before a machine breaks down, on a fixed timetable. |
| Breakdown maintenance | Repair work done only after a machine has already stopped working, usually more costly than preventive maintenance. |
| Downtime cost | The value of production lost while a machine is stopped, whether for a scheduled visit or an unplanned breakdown. |
A machine's payback period is its total investment cost divided by its total monthly saving. Total investment is every one-time cost of getting the machine running: the machine's price, its installation, and any operator training. Total monthly saving is every recurring benefit the machine produces each month, most often the labour time it saves and the downtime it avoids. The division itself must be a formula, never a number worked out once on a separate calculator and typed in, because a typed result silently stops matching reality the moment the price or the saving changes. A shorter payback period is not automatically the right decision on its own; it is one input alongside the machine's expected working life, over which its cost is depreciated, and the factory's cash position.
*A machine's total investment adds every one-time cost, not the machine price alone. Installation and training are real costs of getting a machine running, and leaving them out understates what the factory actually spends.*
What you meet in real life| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Typed total versus formula-driven total | Someone divides once on a calculator and types "20 months" into the sheet, instead of entering the totals as formulas that recalculate the division. | A typed result goes silently wrong the moment the machine price is renegotiated or a saving estimate is revised; a formula never does. |
| Saving counted from labour alone versus labour and downtime combined | Some factories count only the labour hours a machine saves each month; a fuller calculation adds the value of downtime avoided. | Counting downtime saving as well as labour saving gives a shorter, more complete payback period, closer to the machine's real benefit. |
| A machine that runs at less than full use | An automated sewing unit or a fusing press that sits idle part of the month, because there is not always enough work to keep it running. | The real monthly saving is lower than a full-utilisation estimate, so the real payback period is longer; the method stays the same, only the input numbers change. |
| An export, Make to Order machine investment | Delta Garments buys a machine to meet an export buyer's delivery date on a Make to Order line, where the payback period is judged against how many more orders the factory expects to run. | The same formula applies, but the decision is judged against a specific order pipeline, not an average year of general work. |
| A domestic, Make to Stock machine investment | A domestic brand buys a machine for its own forecast-driven production, where monthly saving is judged against a steadier, less order-specific production plan. | The payback formula does not change with market or business model; only the assumptions behind the monthly saving figure do. |
| A hybrid production line | A factory running both export and domestic orders on the same machine spreads its saving across both, and its payback period reflects the combined use. | A machine shared between an export order and a domestic order pays back faster than the same machine used for only one of the two, because its monthly saving is higher. |
Delta Garments is running Make to Order production for an export buyer. Karim, the production manager, receives a supplier's quote for a new machine, framed here as a clearly illustrative teaching example, not a fixed factory fact: the machine's price is USD 8,000 (illustrative), and installation and operator training add USD 500 (illustrative). Karim estimates the machine would save USD 300 (illustrative) a month in labour time by removing a manual step, and a further USD 120 (illustrative) a month in downtime cost, by reducing how often the line stops for a task the new machine automates. Ownership has asked Karim a direct question: does this machine pay for itself quickly enough to approve before the next export order is confirmed?
Using the workbook's own formulas rather than a typed result, the total investment sums the machine's price and its installation and training cost, and the total monthly saving sums its labour saving and its downtime saving.
A common mistake is dividing total investment by total monthly saving once on a calculator, then typing the answer into the workbook as a plain number. The moment the supplier revises the machine's price, or the saving estimate is corrected after a few weeks of real use, that typed figure is now silently wrong until someone remembers to redo the division and retype it. A formula-driven cell never goes stale this way, because it recalculates the instant either total changes.
This lesson is about working out how many months it takes for a machine to earn back what it cost. Add up everything the machine costs to buy and get running: its price, fitting it, and training someone to use it. Add up everything it saves every month: time it saves workers, and stoppages it prevents. Divide the first total by the second, and that tells you how many months pass before the machine has paid for itself. The important habit is to let the spreadsheet do that division as a formula, not to work it out once in your head and type the answer in, because the moment either total changes, a typed answer is wrong and nobody notices.
Karim, the production manager at Delta Garments, is reviewing an illustrative supplier's quote before recommending it to ownership.
The note Karim is about to write into the sheet:
Does typing "20 months" directly into the sheet cause any immediate problem? Decide before opening the answer.
Not immediately — but it creates a hidden risk for every future revision this decision will need.
First fact. Total investment USD 8,500 (illustrative) divided by total monthly saving USD 420 (illustrative) equals about 20.2 months, which rounds to about 20 months today, so the typed figure is not wrong yet.
Second fact. The supplier may still revise the machine's price before the order is placed, and Karim's saving estimate is itself an estimate that could change once the machine is actually running.
The moment either number changes, Karim's typed "20 months" stops matching reality, and nothing in the sheet will flag that it is now wrong until someone remembers to redo the division by hand and retype it. A formula-driven cell recalculates itself the instant the machine price or the saving estimate is updated, so ownership always sees the current payback period, not a snapshot from the day Karim first did the arithmetic.
Framed qualitatively, since the specific dollar figures in this course are illustrative teaching numbers, not fixed facts: a stale, hand-typed payback period that nobody catches can lead a factory to approve a machine that no longer pays back as quickly as the original number suggested, committing cash on the strength of an out-of-date calculation. It can just as easily lead a factory to reject a machine that would now pay back faster than the last typed figure showed, simply because nobody redid the division after the supplier's price or the saving estimate changed. A formula-driven sheet removes this risk entirely, at no cost beyond building the sheet correctly once.
Open the Machine investment payback calculator and go to its "Payback" sheet. The illustrative example column already shows machine price USD 8,000, installation and training USD 500, labour saving USD 300 and downtime saving USD 120, with total investment, total monthly saving and payback period calculated by formula, not typed. In the "Your machine" columns, enter your own machine's price, installation cost and two saving figures, and the sheet calculates your own payback period the same way. Download link: `templates/T08-C06-machine-investment-payback-calculator.xlsx`.
1. Why must a payback-period calculation be entered as a formula rather than typed as a single number?
2. In the illustrative example, what is the payback period when total investment is USD 8,500 and total monthly saving is USD 420?
3. A different illustrative machine costs USD 12,000 to buy and install in total, and saves USD 500 a month. What is its payback period?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Payback period | فترة استرداد الاستثمار | Délai de récupération | Geri ödeme süresi | The time it takes for a machine's total monthly savings to add up to its total investment cost. |
| Preventive maintenance | الصيانة الوقائية | Maintenance préventive | Önleyici bakım | Scheduled inspection and parts replacement done before a machine breaks down, on a fixed timetable. |
| Breakdown maintenance | صيانة العطل | Maintenance corrective | Arıza bakımı | Repair work done only after a machine has already stopped working, usually more costly than preventive maintenance. |
| Downtime cost | تكلفة وقت التوقف | Coût des temps d'arrêt | Duruş maliyeti | The value of production lost while a machine is stopped, whether for a scheduled visit or an unplanned breakdown. |
| Depreciation | الإهلاك | Amortissement | Amortisman | Spreading a machine's purchase cost over its useful working life instead of counting it all in the year it was bought. |
You now know how to calculate a machine's payback period with a formula instead of a typed number. The next lesson turns to a machine a factory already owns, and calculates the real yearly cost difference between maintaining it on schedule and waiting for it to break down. Back to the course map