Course contents
Advanced · Course 6: Machinery Investment and Maintenance · Lesson 2 of 4

Preventive versus breakdown maintenance and their real cost difference

Level: AdvancedTime: 45 minutesOrder used: None (illustrative machine, not Order A or Order B, the jeans order)Tool: Machine investment payback calculator
This lesson is for anyone who owns or manages equipment and decides how much to spend keeping it running: a factory owner, a domestic brand's operations manager, or a merchandiser reviewing a maintenance proposal. No previous lesson is required. Every dollar figure is a clearly flagged illustrative number, not a fixed academy fact.
Domestic brandCedar & Co. (local brand), running its own packing equipment
Preventive maintenanceScheduled visits USD 240 plus parts USD 160 (illustrative)
Breakdown maintenanceRepair calls USD 420 plus downtime USD 610 (illustrative)
DifferenceUSD 630 a year more for breakdown maintenance (illustrative)
Business modelMake to Stock, domestic
Decision-makerOmar, owner of Cedar & Co.
02Opening

This page explains how to calculate and compare preventive maintenance cost against breakdown maintenance cost for a machine already owned

This page explains how to calculate the yearly cost of maintaining a machine on a fixed schedule, and compare it against the cost of only fixing it after it breaks down. This matters to a factory owner or a domestic brand's operations manager deciding how much to spend on upkeep, and to a merchandiser reviewing a maintenance proposal.

Cedar & Co., the domestic brand used in this lesson, runs its own packing and labelling equipment for its Make to Stock production, ahead of sending finished goods to its shops. Omar, its owner, has to decide how much to spend keeping that equipment running: on a fixed preventive schedule, or by waiting for it to break down.

Without this skill, an owner compares only the visible repair bill against the preventive contract's price and concludes breakdown maintenance looks almost as cheap. That comparison leaves out the value of production lost while the machine sat stopped, and it can lead a brand to under-invest in scheduled maintenance. This lesson gives you the formula-driven method that compares the two options fairly, every time.

03Before you start

What you need, and what this lesson does not cover

You need: lesson 6.1's payback-period method is useful background, though this lesson can be read on its own.

By the end of this lesson you can:

  • state the rule that a fair maintenance comparison adds every cost component on each side before comparing totals;
  • calculate a preventive-maintenance total and a breakdown-maintenance total by formula, never a typed number;
  • explain why downtime cost must be included in the breakdown-maintenance total, not just the repair invoice;
  • name the real yearly cost difference between preventive and breakdown maintenance for an illustrative machine;
  • recognise when a machine's ageing condition means the comparison should be redone rather than trusted from an old calculation.

Not covered here: calculating a new machine's payback period from labour and downtime saving (lesson 6.1), building the maintenance schedule that produces a preventive-maintenance total and tracking its running cost (lesson 6.3), and combining an old machine's rising maintenance cost with a new machine's payback period to decide whether to replace it (lesson 6.4).

04Key terms

Words you will meet in this lesson

TermMeaning
Preventive maintenanceScheduled inspection and parts replacement done before a machine breaks down, on a fixed timetable.
Breakdown maintenanceRepair work done only after a machine has already stopped working, usually more costly than preventive maintenance.
Downtime costThe value of production lost while a machine is stopped, whether for a scheduled visit or an unplanned breakdown.
Payback periodThe time it takes for a machine's total monthly savings to add up to its total investment cost.
DepreciationSpreading a machine's purchase cost over its useful working life instead of counting it all in the year it was bought.
05Teaching
The rule

A fair comparison of preventive and breakdown maintenance adds every cost component on each side, calculated by formula, before comparing the two totals

Preventive maintenance cost is the sum of every scheduled visit and every part replaced on a fixed timetable, calculated by formula. Breakdown maintenance cost is the sum of every emergency repair call and the downtime cost while the machine sits stopped, also calculated by formula, never typed. Comparing the two totals, never a single line item from one side against a single line item from the other, shows the real cost difference between waiting for a machine to fail and maintaining it on schedule.

Preventive maintenance total (illustrative):
scheduled visits USD 240 + parts replaced on schedule USD 160
= USD 400 per year

*Preventive maintenance's total adds every scheduled cost component, not the visit fee alone. Parts replaced on a fixed timetable are a real, recurring cost of the preventive approach, and leaving them out understates it.*

What you meet in real life

The same comparison rule applies to any machine, but what gets counted, and how completely, changes whether the comparison is fair

What can differThe shapes you meetWhy it matters
Comparing only the repair billLooking only at the emergency repair invoice and concluding breakdown maintenance is cheap, while ignoring the downtime cost of the machine sitting stopped during production hours.This makes breakdown maintenance look artificially cheap, since lost production time is a real cost the invoice never shows.
Comparing full costs including downtimeAdding the downtime cost to the repair bill before comparing it against the preventive maintenance total.Gives the true cost difference, the only basis on which to decide how much scheduled maintenance is worth.
A machine with a supplier service contractAn imported machine bundles its scheduled visits into one annual fee from the supplier.The comparison method stays the same; the preventive side is simply already summed for you in the contract price.
A machine near the end of its useful lifeAs a machine ages, breakdown frequency, and so breakdown cost, tends to rise even if the preventive schedule stays the same.The comparison should be redone periodically, not calculated once and trusted forever.
A domestic Make to Stock brand's own equipmentCedar & Co. maintains its own packing and labelling equipment for stock it produces to its own forecast, not to a single order's deadline.The comparison method does not depend on market or business model; only how urgently a stoppage disrupts a specific delivery date differs.
An export factory's shared equipmentDelta Garments maintains equipment shared across several export orders, where a breakdown risks missing more than one buyer's delivery date at once.The same formula applies, but the cost of a breakdown's downtime can be higher when several orders depend on the same machine.
The case we follow

Omar, the owner of Cedar & Co., reviews a maintenance proposal for the packing equipment his domestic brand depends on

Cedar & Co. runs its own packing and labelling equipment ahead of sending Make to Stock goods to its 12 shops. Omar, its owner, is reviewing an illustrative maintenance comparison for this equipment, framed here as a clearly illustrative teaching example, not a fixed brand fact: preventive maintenance costs USD 240 (illustrative) a year in scheduled visits plus USD 160 (illustrative) a year in parts replaced on schedule. Breakdown maintenance costs USD 420 (illustrative) a year in emergency repair calls plus USD 610 (illustrative) a year in downtime cost while the equipment sat stopped. Omar has to decide whether the preventive schedule is worth its price.

Preventive (illustrative)Scheduled visits USD 240Parts replaced USD 160Breakdown (illustrative)Repair calls USD 420Downtime cost USD 610
Cedar & Co.'s illustrative preventive and breakdown totals each add two cost components, per year. Each component sits on its own row so both totals can be summed by formula, not by hand.
The worked number

Calculating the real yearly cost difference between preventive and breakdown maintenance for this illustrative equipment

Using the workbook's own formulas, the preventive total sums scheduled visits and parts replaced, the breakdown total sums repair calls and downtime cost, and the difference subtracts one total from the other.

Breakdown maintenance total (illustrative):
emergency repair calls USD 420 + downtime cost while stopped USD 610
= USD 1,030 per year
Difference (illustrative):
breakdown total USD 1,030 − preventive total USD 400
= USD 630 more per year for breakdown maintenance
PreventiveUSD 400/yearBreakdownUSD 1,030/year (repair 420 + downtime 610)Breakdown costs USD 630 more per year than preventive, once downtime is counted
Breakdown maintenance costs USD 630 a year more than preventive maintenance on this illustrative equipment. The gap only appears once downtime cost is added; the repair invoice alone (USD 420) looks close to the preventive total (USD 400).
The method

How to build a correct, formula-driven preventive-versus-breakdown comparison for any machine

  1. List every preventive-maintenance cost component — scheduled visits, scheduled parts — in its own row and sum them with a formula.
  2. List every breakdown-maintenance cost component — emergency repair calls, downtime cost while stopped — in its own row and sum them with a formula, making sure downtime cost is included, not just the repair invoice.
  3. Subtract the preventive total from the breakdown total with a formula to see the real difference, not an impression from a single invoice.
  4. Never compare a single line item from one side against a single line item from the other, since that comparison always favours whichever side has the smaller isolated number.
  5. Revisit the comparison periodically, since an ageing machine's breakdown cost tends to rise even when its preventive schedule stays unchanged.
The trap

Comparing only the repair-call cost of breakdown maintenance against the full preventive-maintenance total, leaving out the downtime cost

A common mistake is looking at an emergency repair invoice, seeing it costs only slightly more than the preventive contract's total, and concluding the two options cost about the same. This makes breakdown maintenance look artificially cheap, because the value of lost production time while the machine sat stopped was never counted, and it can lead a factory or brand to under-invest in scheduled maintenance and accept more unplanned stoppages than the true cost comparison justifies.

06In plain words

This lesson compares two ways of keeping a machine running: fixing small things on a schedule before they become big problems, or waiting until something breaks and fixing it then. Add up everything the scheduled approach costs: the visits, and any parts replaced. Add up everything the wait-and-fix approach costs: the repair calls, and the value of all the production lost while the machine sat still. Comparing only the repair bill against the scheduled cost hides the real difference, because the repair bill never shows what was lost while the machine was not working. Once you add that lost time in, waiting for a breakdown is usually the more expensive choice, sometimes by a wide margin.

07Quick check
  • Preventive maintenance total adds scheduled visits and scheduled parts, not the visit fee alone.
  • Breakdown maintenance total adds repair calls and downtime cost, not the repair invoice alone.
  • Comparing only a repair invoice against a preventive total hides the real cost of lost production time.
  • The comparison is two full totals against each other, never one line item from each side.
  • An older machine's breakdown cost tends to rise even if its preventive schedule stays the same.
  • The same comparison method applies whether the machine belongs to a domestic brand or an export factory.
08Workplace scenario

Omar sees an emergency repair invoice close in price to the preventive contract and is tempted to conclude the two options cost about the same

Omar, the owner of Cedar & Co., is reviewing an illustrative maintenance proposal for the brand's own packing equipment.

  • The last emergency repair call cost USD 420 (illustrative) — only slightly more than the preventive maintenance contract's USD 400 (illustrative) total.
  • The downtime cost of the equipment sitting stopped during that repair was USD 610 (illustrative), not yet added to Omar's comparison.
  • Omar is about to conclude that preventive maintenance and breakdown maintenance cost roughly the same, based on the repair invoice alone.
  • The preventive contract's full yearly total is USD 400 (illustrative): scheduled visits USD 240 plus parts replaced USD 160.

The two figures side by side, as Omar first sees them:

Repair invoice (illustrative): "USD 420" Preventive contract total (illustrative): "USD 400"

Is comparing the repair-call cost alone against the preventive total a fair comparison? Decide before opening the answer.

Show decision

No. The repair-call cost alone leaves out the downtime cost, and that omission hides the real difference.

First fact. The repair-call cost alone, USD 420 (illustrative), does not include the USD 610 (illustrative) downtime cost of the equipment sitting stopped while it was fixed.

Second fact. The fair comparison is breakdown maintenance's full total (420 + 610 = USD 1,030, illustrative) against preventive maintenance's full total (USD 400, illustrative).

That is a difference of USD 630 (illustrative) a year, not the roughly USD 20 difference the repair-call-only comparison would suggest. Omar's brand would be underestimating the real cost of breakdown maintenance by more than thirty times if he stopped at the repair invoice alone.

09What it costs

The risk of under-investing in preventive maintenance because a repair invoice alone looked almost as cheap

Framed qualitatively, since the specific dollar figures in this course are illustrative teaching numbers, not fixed facts: comparing only the repair invoice while ignoring downtime cost can make breakdown maintenance look nearly as cheap as preventive maintenance, when in reality the full cost, once lost production time is included, is substantially higher. A domestic brand or export factory that makes this comparison mistake can under-invest in scheduled maintenance and accept far more unplanned stoppages than the true cost comparison would ever support, paying the difference in repeated downtime rather than in one predictable, scheduled cost.

10Working template

Machine investment payback calculator: enter the illustrative figures, then your own equipment's figures, in the Maintenance cost sheet

Open the Machine investment payback calculator and go to its "Maintenance cost" sheet. The illustrative example column already shows scheduled visits USD 240, parts replaced USD 160, emergency repair calls USD 420, and downtime cost USD 610, with both totals and their difference calculated by formula. In the "Your machine" columns, enter your own equipment's four figures, and the sheet calculates your own comparison the same way. Download link: `templates/T08-C06-machine-investment-payback-calculator.xlsx`.

Download the Machine investment payback calculator (Excel)

11Check yourself

1. Why must downtime cost be included in the breakdown maintenance total, not just the repair-call cost?

2. In the illustrative example, what is the difference between breakdown maintenance total (USD 1,030) and preventive maintenance total (USD 400)?

3. What typically happens to a machine's breakdown-maintenance cost as it gets older, even if its preventive schedule stays the same?

12Glossary
ENARFRTRMeaning
Payback periodفترة استرداد الاستثمارDélai de récupérationGeri ödeme süresiThe time it takes for a machine's total monthly savings to add up to its total investment cost.
Preventive maintenanceالصيانة الوقائيةMaintenance préventiveÖnleyici bakımScheduled inspection and parts replacement done before a machine breaks down, on a fixed timetable.
Breakdown maintenanceصيانة العطلMaintenance correctiveArıza bakımıRepair work done only after a machine has already stopped working, usually more costly than preventive maintenance.
Downtime costتكلفة وقت التوقفCoût des temps d'arrêtDuruş maliyetiThe value of production lost while a machine is stopped, whether for a scheduled visit or an unplanned breakdown.
DepreciationالإهلاكAmortissementAmortismanSpreading a machine's purchase cost over its useful working life instead of counting it all in the year it was bought.
13Next

Lesson 6.3: Building a machine maintenance schedule and tracking its own cost

You now know how to compare preventive and breakdown maintenance cost for a machine you already own. The next lesson builds the schedule behind that preventive-maintenance figure, showing exactly which tasks and intervals produce it, and how to track whether the schedule is actually being followed. Back to the course map

14Ladder

RecognizeName the components that belong in a preventive-maintenance total and a breakdown-maintenance total.
ConnectSee why downtime cost must be added to the repair invoice before comparing breakdown maintenance against preventive maintenance.
CompareTell a fair full-total comparison apart from an unfair single-line-item comparison.
DecideJudge whether a preventive maintenance schedule is worth its price, based on the real yearly cost difference.