A machine described by two numbers

A tracked excavator, EX-17, is six years old and has 6,000 hours on the meter. For most software demonstrations, that is enough information to schedule service. For a maintenance organisation, it is barely a description.

Here is what else is true about the same machine.

  • Roughly 1,200 of those hours were idle, with the engine running and the machine producing nothing.
  • About 900 hours were worked with a hydraulic breaker attached.
  • It has operated on several jobsites, in different ground conditions.
  • Its application changed: it started in general excavation and later moved to heavier demolition-type work.
  • Different operators have run it, with different techniques and different reporting habits.
  • The engine was rebuilt at 4,800 machine hours.
  • The undercarriage has already been replaced once.
  • The breaker it used is now mounted on a different machine.
  • An operator reported that hydraulic response feels different once the machine gets hot.
  • A preventive service is approaching.
  • Its next assignment is high-utilisation work at a remote site.

This guide will not diagnose EX-17. The point is not the machine's condition. The point is that two numbers, age and hours, describe almost none of what a maintenance organisation actually needs to know.

The hour meter tells you how much use accumulated. Heavy equipment maintenance has to understand the life the machine accumulated during that use, and what life it is about to live next.

Why mobile heavy equipment is a different maintenance problem

A stationary machine sits in one place, does one job, is served by one team and keeps one identity. A heavy machine does none of that reliably.

Heavy equipment accumulates maintenance history while its location, application, configuration, operator, utilisation, component lifecycles and operational importance keep changing underneath that history.

The software problem is not scheduling service. It is preserving continuity of the machine while its operating context keeps changing.

Three guides on this site ask related but distinct questions. Equipment Maintenance Software asks what an organisation should learn about one piece of equipment as maintenance accumulates across its life. Plant Maintenance Software asks how to change equipment condition without losing control of an operating plant.

This guide asks a third question: how do you preserve and act on maintenance knowledge when the machine moves through different locations, applications, configurations, operators and levels of operational importance?

Model 1 — the machine life model

Our first model, a CMMSBuyersGuide synthesis, separates three things that heavy-equipment decisions constantly confuse.

PAST DUTY HISTORY → PRESENT CONDITION → FUTURE ASSIGNMENT

ElementWhat it tells you
Past duty historyHow the machine has actually been used, and therefore what exposure produced its current state
Present conditionWhat inspection, analysis, machine data and operator observation say about it now
Future assignmentWhat the organisation is about to ask the machine to do, which determines what its condition means operationally

The machine's past helps explain its condition. Its future determines what that condition means.

A worn component on a machine about to be parked is a different decision from the same component on a machine about to work twelve-hour days four hours from the nearest shop.

Not every hour tells the same story

An hour meter counts exposure. It does not describe it. Manufacturer telematics systems already distinguish between different kinds of hours.

Komatsu's Komtrax reporting, for example, separates working hours from figures such as actual working hours, travel hours, digging hours and swing hours, and reports idling alongside them. [1] Capability varies by machine, market and telematics package, and this guide should not be read as saying every manufacturer exposes the same data points.

Kind of hourWhat it approximately represents
Engine hoursTime the engine ran, productive or not
Idle hoursEngine running without producing work
Productive or work-mode hoursTime the machine was actually performing its function
Application-specific hoursTime in a specific mode or with a specific attachment, such as breaker hours

A meter is a useful proxy for exposure. It is not a complete description of it.

This matters immediately for cost. Suppose EX-17 accumulated $30,000 in maintenance spend over 1,000 engine hours, of which 700 were productive. That is $30 per engine hour, or roughly $42.86 per productive hour. Neither figure is automatically correct.

A cost-per-hour metric is only meaningful when you know what kind of hour is in the denominator.

The same logic applies to counts of anything else. Failures, callouts, fluid top-ups and unplanned repairs become more meaningful when related to the exposure that produced them, rather than reported as raw totals across machines that worked very differently.

Duty history: the story behind the meter

Duty history is a CMMSBuyersGuide term for the accumulated story of how a machine has actually been used. It generally includes:

  • Application — what kind of work the machine performed
  • Load and operating mode — how hard it was worked and in what mode
  • Environment — ground conditions, materials, terrain, climate, contamination
  • Idle versus productive use
  • Configuration — what attachments and arrangements it ran with
  • Operation — who ran it and how
  • Condition response — what inspections, analyses and repairs found along the way

Duty context enriches the meter. It does not replace it, and it does not justify inventing a universal severity score.

Consider two machines. EX-17 and EX-18 both show 5,000 hours. EX-17 worked in abrasive, wet material on sloped ground with frequent tracking between working positions. EX-18 worked on prepared, level, relatively clean sites with short moves.

Caterpillar's undercarriage guidance is explicit that wear depends on factors including the application, the ground and materials the machine works in, operating technique, track adjustment and cleaning practice, rather than on hours alone. [2]

That is manufacturer guidance about undercarriage systems specifically. The broader lesson for buyers is narrower than it sounds and more useful than it looks: identical meter readings do not imply identical accumulated exposure.

Two machines with the same hours may have lived different lives.

Undercarriage makes the teaching example concrete. Knowing that a machine has 4,000 hours on its undercarriage answers less than knowing what it did, where and how during those hours, and what actual wear measurement now shows. This guide does not predict component life. It argues that usage numbers, duty context and measured condition are three different pieces of evidence, and software should keep all three.

Idle time and why hours are not homogeneous

EX-17's 1,200 idle hours are the clearest illustration. Those hours accumulated on the meter. Interval-based service moved closer. The machine produced little during them.

A machine can consume maintenance interval without producing equivalent productive work.

This guide does not claim idle hours are harmless, and it does not claim they cause the same wear as working hours. What it claims is narrower: if your maintenance intervals, cost metrics and utilisation reporting all run on a single undifferentiated hour count, you are treating very different hours as interchangeable, and manufacturer telematics already tells you they are not.

Attachments have lives of their own

Heavy equipment is reconfigurable, and that breaks the assumption that maintenance history belongs to one machine.

AttachmentAccumulated useCurrently mounted on
H-4 hydraulic breaker900 hoursEX-22
B-7 bucket2,800 hoursEX-17
A-2 specialised attachment400 hoursIn the yard

These are illustrative figures for one organisation's tracking practice, not universal meter types. Attachments are not always metered, and how usage is captured varies widely.

Two consequences follow. First, an attachment's history should stay with the attachment when it moves between base machines: H-4's 900 hours belong to H-4, not to whichever excavator currently holds it. Second, the machine's own history should still record that it did that work.

EX-17's 600 hours of breaker work still matter in EX-17's history after the breaker moves to another machine.

Breaker work is a different duty context from bucket work. If the configuration history disappears when the attachment is unbolted, the machine's duty history develops a hole precisely where its hardest use was recorded.

Heavy-equipment relationships are temporary. The maintenance consequences of those relationships stay in history.

Model 2 — multiple lifecycles

Ask a simple question about a machine with 12,000 hours: how old is it?

ElementStatus
Machine12,000 lifetime hours
EngineRebuilt at 10,000 hours — 2,000 hours since rebuild
UndercarriageReplaced at 11,000 hours — 1,000 hours since replacement
Hydraulic systemOriginal — 12,000 hours
H-4 breakerIndependent history, currently on another machine

A heavy machine does not necessarily have one maintenance age.

Machine age and component age diverge as soon as major maintenance begins. A single asset record with one number in it cannot express the table above, and the table above is the actual maintenance situation.

Lifetime age and current lifecycle age are different, and both can be correct answers to “how old is this machine?”

Manufacturer rebuild programmes make this explicit. Caterpillar's Certified Rebuild programme describes rebuilding a machine to like-new condition with a defined test and parts-replacement scope, applying engineering updates, and issuing the rebuilt machine a new identification number so the rebuild is recorded as a new reference point in the machine's life. [3]

That is one manufacturer's programme, applied to specific machines under specific conditions. It should not be read as meaning every rebuild resets every machine, or that a rebuild erases what came before.

A lifecycle reset creates a new maintenance reference point. It should not destroy lifetime history.

Rebuild scope is part of the record

A record that says “rebuilt at 10,000 hours” is incomplete. The maintenance question is what was rebuilt.

  • Which systems and components were replaced, reconditioned, tested or left alone?
  • Which component lifecycles were reset, and which continued accumulating?
  • Were engineering updates or configuration changes applied?
  • What was the machine's condition evidence at the time of the work?

Without scope, a rebuild entry tells a future decision-maker that something significant happened and nothing about what it means. With scope, the machine's lifecycle table stays honest for the rest of its life.

Machine, component and attachment lineage is a practical record-keeping requirement, not a digital-twin ambition.

Model 3 — the heavy equipment evidence stack

Condition is not established by one source. Our third model, again a CMMSBuyersGuide synthesis, lists the evidence a heavy-equipment organisation typically has.

MACHINE SIGNALS → OPERATOR OBSERVATION → PHYSICAL INSPECTION → CONDITION ANALYSIS → MAINTENANCE HISTORY → DUTY CONTEXT

This mirrors how manufacturer condition-monitoring practice is described. Caterpillar's condition-monitoring material describes evaluating electronic and telematics data, fluid analysis, equipment inspections, service history and site or operating context together, so that repairs can be planned before failure rather than after it. [4]

Usage predicts exposure. Condition evidence tests whether the prediction matched reality.

This guide does not claim condition monitoring predicts failure reliably, and it does not suggest condition evidence replaces manufacturer preventive maintenance requirements.

Operator observation is evidence, not diagnosis

EX-17's operator reported that hydraulic response feels different when the machine gets hot. That report is valuable precisely because it is descriptive.

The operator should report what the machine did. Guessing the component is someone else's job.

Three software behaviours follow from treating operators as part of the loop rather than as an input device.

  1. Capture the observation without requiring the operator to categorise it technically.
  2. Give the observation a disposition. An observation that does not become a work order may still deserve a recorded decision — monitored, deferred, referred, investigated or closed with a reason.
  3. Return the outcome. When the machine is worked on, the operator who reported the symptom should be able to learn what was found.

Machine knowledge should survive operator changes.

If Operator A reports a symptom, maintenance decides to monitor it, and Operator B takes the machine next shift, the question is whether Operator B can know any of that. On mobile equipment moving between sites and crews, the alternative to a recorded observation is usually nothing at all.

Telematics is a signal, not a conclusion

Connected heavy equipment produces a lot of data. Each step below is a different thing, and collapsing them causes real operational damage.

TELEMATICS EVENT → CONFIRMED FAULT → MAINTENANCE NEED → WORK ORDER

Connected equipment can generate more signals than an organisation can intelligently act on.

Three systems are usually involved, and they do different jobs.

SystemPrimary role
TelematicsDescribes machine behaviour, location, usage and events
Manufacturer or dealer service systemsHold machine-specific diagnostics, service information and programme history
Maintenance management softwareTurns relevant evidence into controlled decisions, work and preserved history

None of these should be expected to replace the others. A maintenance system that tries to become a diagnostic system usually does both jobs poorly.

Connectivity moves data. Integration preserves meaning.

A vendor saying “we integrate telematics” has said nothing yet. The buyer's question is what information actually crosses the boundary, in what form, how often, and what it is allowed to trigger.

Mixed fleets and data standards

For fleets with machines from several manufacturers, a shared data specification helps. ISO/TS 15143-3, developed from the AEM and AEMP telematics standard work, defines a common way for machines from different manufacturers to report a defined set of telematics data such as hours, location, fuel use and similar fields. [5] Komatsu's telematics documentation describes support for that standardised exchange as the route to mixed-fleet reporting. [6]

A common standard improves interoperability for a defined set of fields. It does not make every manufacturer's data identical, and it does not mean rich machine-specific data is available through it.

“Telematics integration” becomes a meaningful claim only when the buyer knows which fields actually cross the boundary.

Meter freshness and provenance

Usage-based maintenance runs on a number that is often older than it appears. A meter value can arrive from telematics, from a technician reading, from an operator entry or from a service record, and each has different timing and reliability.

A meter value without a timestamp creates false maintenance certainty.

A defensible meter record carries three things: the value, its source, and when it was taken. Everything downstream — due calculations, cost per hour, utilisation, forecasting — inherits the quality of that record.

Maintenance has to reach a machine that moves

Stationary maintenance has a geography problem only in the sense that the shop is elsewhere. Mobile equipment has three distinct locations.

LocationMeaning
Operating locationWhere the machine is working
Discovery locationWhere the problem was noticed or the machine stopped
Service locationWhere the maintenance will actually happen

Field service, yard service, shop service and dealer service are all legitimate answers, and the right one depends on the work, the parts, the tools, the risk and the assignment. This guide does not prescribe which is correct.

The support footprint

Support footprint is our term for what has to reach the machine before maintenance can actually happen.

  • A technician with the right capability
  • Parts and consumables
  • Tools and diagnostic equipment
  • A service vehicle
  • A specialist, where needed
  • Technical information for that machine and configuration
  • Lifting or support equipment
  • Transport or recovery capability, where relevant

Diagnostic uncertainty has a travel cost. The farther maintenance is from the machine, the more expensive incomplete information becomes.

First-trip readiness — knowing enough before departure that the visit can plausibly accomplish something — is a planning concept, not a promise. No system guarantees a first-visit fix. Systems differ enormously in how much the technician can know before leaving.

Repair duration is not the same as total maintenance response.

A two-hour repair can consume a day when travel, access, parts retrieval and return are counted. Reporting only wrench time on mobile equipment systematically understates what maintenance costs the operation.

Due and not due is not enough

EX-17 has a preventive service at 6,000 hours and its meter reads 5,920. Eighty hours remain. A system that reports “not due” has answered the wrong question.

Eighty hours is roughly two weeks at light utilisation and less than a week at twelve hours a day.

The same remaining interval can represent very different calendar urgency.

Due trajectory

Due trajectory is our term for combining a current, trustworthy meter value with expected near-term utilisation to estimate when the machine will actually approach its threshold. It is a planning estimate. It does not override manufacturer requirements, and it is only as good as the meter and the utilisation assumption behind it.

TRUSTWORTHY METER → EXPECTED UTILISATION → ESTIMATED APPROACH TO THRESHOLD → PLANNING DECISION

The next job can change today's maintenance priority.

Service intercept

Service intercept is our term for a planned point where four things align: machine movement, available downtime, approaching maintenance demand and available maintenance capability.

EX-17 finishes at Site A on Friday and starts at Site B on Monday, and the route passes the yard. That transition is a maintenance opportunity created by the operation itself rather than by the maintenance schedule.

The best maintenance opportunity is often created by the machine's movement through the operation.

Finding intercepts is a scheduling and planning discipline rather than a software feature.

The guides on maintenance planning and maintenance scheduling cover the readiness and commitment mechanics that make an intercept usable. Nothing here suggests extending or violating manufacturer service requirements to reach one.

Model 4 — the mobile maintenance loop

The four ideas above combine into one loop. This is our synthesis and the master model of this guide.

ASSIGN → OPERATE → ACCUMULATE EXPOSURE → OBSERVE AND MONITOR → INTERPRET → FORECAST MAINTENANCE DEMAND → FIND SERVICE INTERCEPT → PREPARE SUPPORT FOOTPRINT → EXECUTE → VERIFY → UPDATE LIFECYCLE → HAND BACK → REASSIGN → OBSERVE AGAIN

Heavy-equipment maintenance demand moves through the operation with the machine.

Every step of that loop can lose information. The assignment is recorded in one place, the exposure in another, the observation nowhere, the intercept in a phone call, the rebuild scope in a paper invoice. What a buyer is actually evaluating is how much of the loop survives in one connected history.

Condition belongs to the machine; consequence belongs to the assignment

A worn component is a property of the asset. What its failure would cost is a property of the work the machine is assigned to.

Machine condition and assignment criticality are different things, and no universal scoring formula turns one into the other.

Two further distinctions matter at fleet level.

  • Machine availability is not fleet capability. Substitutes, redundancy, specialised configuration, rental options and work sequencing all change what one machine's downtime actually costs.
  • Maintenance investment should see future utilisation. Spending decisions made against a machine's past are made against information that has already stopped being relevant.

Repair, rebuild, retain or replace

Eventually, the question stops being what to fix and becomes what future capability the organisation wants to buy with the next maintenance dollar.

OptionWhat it buys
RepairReturn to service now, with the machine's existing lifecycles intact
RebuildA new reference point for defined systems, at defined cost and scope
Retain with managed riskContinued service with known limitations and monitoring
ReplaceDifferent capability, different cost structure, no accumulated history

There is no defensible universal percentage rule for this decision. Research on public fleet replacement generally works from cost history rather than a single threshold.

Work developed for the Texas Department of Transportation argues that the most useful information in a life-cycle cost record is its trend: units whose life-cycle costs have been rising for longer, or rising faster, warrant higher replacement priority than units judged against a fixed annualised cost threshold. [7]

Recent cost behaviour can matter as much as a lifetime total.

That is research developed for one public fleet's replacement programme, and it should not be treated as a universal replacement model. The transferable lesson is that recency and concentration of cost are information that a lifetime average destroys.

Two further cautions. Sunk history should not justify continued spending: money already spent on EX-17 is not an argument for spending more. And a machine that can be repaired is not automatically a machine worth repairing.

Lifecycle convergence

Lifecycle convergence is our term for what happens when several major components approach significant intervention within a similar horizon. Individually, each is a repair decision. Together, they can become one machine-level economic decision.

When lifecycles converge, the whole machine becomes the unit of decision.

No specific number of converging components triggers replacement. The value of noticing convergence is that it changes the question being asked, before the organisation answers four separate questions that were really one.

Good software makes the evidence visible without manufacturing certainty. It should support the decision, not make it.

Distinctions worth keeping

ThisIs not this
Engine hoursProductive hours
Machine ageComponent age
Lifetime ageCurrent lifecycle age
A meter readingA current meter, without freshness and source
Operator observationDiagnosis
Telematics eventConfirmed fault
Confirmed faultAutomatic work order
Machine conditionAssignment criticality
Machine locationService location
Technician availableField work ready
Repair durationTotal maintenance response
ConnectedIntegrated
Work order closedOperator feedback loop closed
RepairableEconomically worth repairing

What the software actually has to do

Only now do capabilities make sense, because each one below exists to solve a problem described above.

  • Preserve meter data with its source and freshness, alongside its value
  • Support usage-based maintenance without losing calendar and condition requirements
  • Preserve duty context — application, environment, mode and configuration — alongside hours
  • Track machine lifecycles and component lifecycles separately
  • Track attachments as assets with independent histories
  • Preserve temporary machine-to-attachment relationships in history after they end
  • Capture operator observations without requiring technical diagnosis
  • Record the disposition of an observation, including when no work order results
  • Combine telematics, inspection, condition analysis and history in one view
  • Handle mixed-fleet data without pretending different manufacturers report identically
  • Forecast the approach to usage-based service rather than reporting due and not due
  • Use future assignment information in maintenance planning
  • Support the decision between field service and shop service
  • Support field-service preparation: parts, tools, information and access
  • Preserve machine location context over time
  • Support rebuilds without erasing lifetime history
  • Preserve rebuild scope as well as the rebuild date
  • Roll cost and downtime up to machine and component level
  • Surface recent cost behaviour separately from lifetime totals
  • Support repair, rebuild and replace analysis without pretending software makes the decision

The information-quality foundation under all of this is covered in maintenance tracking software, and the condition-evidence side in predictive maintenance software.

Buyer questions

Meters and usage

  • What meter types can the system hold for one machine?
  • Where does each meter value come from, and is the source recorded?
  • Is every meter value timestamped, and is staleness visible?
  • What happens when telematics and a technician reading disagree?
  • Can a corrected meter value be entered without destroying the previous record?
  • Can idle and productive time be reported separately where the machine provides them?
  • Can cost per hour be reported against more than one kind of hour?

Duty context

  • Can the system record application, environment and operating mode over time?
  • Can duty context be reported alongside cost and failure history?
  • Can two machines with similar hours be compared on how they were used?

Attachments and configuration

  • Are attachments tracked as assets with their own history?
  • Can an attachment's usage follow the attachment between base machines?
  • Does the base machine retain a record of the work it did with that attachment?
  • Can current and historical machine-to-attachment relationships both be seen?

Lifecycles and rebuilds

  • Can the system show machine age and component ages at the same time?
  • Can a component lifecycle be reset without erasing lifetime history?
  • Is rebuild scope recorded — what was replaced, reconditioned and left alone?
  • After a rebuild, can someone still see everything that happened before it?
  • Can several components' approaching intervention points be seen together?

Operators and observations

  • Can an operator report a symptom without selecting a technical cause?
  • Does every observation get a recorded disposition, including “monitor”?
  • Can a later technician see prior observations on that machine?
  • Can the reporting operator learn what was found?
  • Can recurrence of the same symptom be seen over time?

Telematics and integration

  • Exactly which telematics fields cross into the maintenance system?
  • How often are they updated, and what happens when the machine is out of coverage?
  • Which events are allowed to create work automatically, and who controls that?
  • How are machines from different manufacturers handled?
  • What happens to a telematics event that no one acts on?

Field service and planning

  • What can a technician see about a machine before travelling to it?
  • Can parts, tools and information be prepared against a field job?
  • Can the system show where the machine is and where it will be?
  • Can total maintenance response time be reported, including travel?
  • Can the system show how soon a usage-based service will be reached at expected utilisation?
  • Can an upcoming assignment change the priority of planned work?

Economics and decisions

  • Can cost be seen at machine, component and attachment level?
  • Can recent cost behaviour be separated from lifetime totals?
  • Can downtime be attributed to the machine and to the assignment it affected?
  • Does the system present evidence for repair, rebuild and replace decisions without reducing them to a score?

Six vendor demonstrations

Each of these uses real fleet situations rather than feature tours. Give the vendor the scenario and watch what the software can actually show.

Demo 1 — due trajectory

EX-17's meter reads 5,920 against a 6,000-hour service. Ask the system what it tells you. Then add that next week the machine is assigned twelve-hour days at a remote site, and that it finishes at Site A on Friday and passes the yard before starting Site B on Monday.

  • Can the system show when the threshold will actually be reached at expected utilisation?
  • Can it surface the Friday-to-Monday movement as a natural service opportunity?
  • Where did the 5,920 come from, and when was it taken?

Demo 2 — component lifecycles

A machine has 12,000 hours. The engine was rebuilt at 10,000. The undercarriage was replaced at 11,000. The hydraulic system is original.

  • How old is this machine, according to the software?
  • How old is each major component?
  • What was reset at the rebuild, and what continued accumulating?
  • What did the rebuild include, and can you still see the pre-rebuild history?

Demo 3 — attachment history

The H-4 breaker has 900 hours and moved from EX-17 to EX-22.

  • Can you see H-4's complete history and which machines it worked on?
  • Does EX-17 still show that it did breaker work?
  • Is H-4's cost and maintenance history separate from either machine's?

Demo 4 — the remote machine

An operator reports that hydraulic response feels slower when the machine gets hot. The machine is four hours from the shop. Do not let the vendor diagnose the machine — that is not the test.

  • What can the technician know about this machine before leaving?
  • What prior observations, inspections, analyses and repairs are visible?
  • How does the system reduce the chance that the first visit becomes only a diagnostic trip?

No system should promise first-trip resolution. What differs is how much the technician can learn before departure.

Demo 5 — operator feedback

Operator A reports a symptom. Maintenance decides to monitor it. The shift changes.

  • What does Operator B know when taking the machine?
  • After the work is eventually done, is the observation linked to what was found?
  • When the symptom returns three months later, can the system show the recurrence?

Demo 6 — repair, rebuild or replace

Ask what evidence the system can assemble about one ageing machine before a decision is made. Then reveal that three other major components are also approaching significant intervention.

  • Can the system show these as one machine-level investment decision rather than four repairs?
  • Can it separate recent cost behaviour from the lifetime total?
  • Does it present evidence, or does it try to produce a verdict?

Back to EX-17

We started with a six-year-old excavator with 6,000 hours. By now, that description is visibly inadequate.

What a maintenance organisation actually needs to know is what duty the machine accumulated, which attachments it ran and for how long, what operators observed and whether anyone acted on it, what inspections and analyses found, what was rebuilt and to what scope, how old each component now is, what remains unresolved, where the machine is, what it will be asked to do next, how soon its next service will actually arrive, where maintenance can intercept it, and which of its lifecycles are converging.

The goal is not the most detailed record. It is preserving the evidence that changes maintenance decisions.

Heavy equipment maintenance software should help you understand the life the machine has lived, the condition it is in now, and whether it is ready for the life you are about to ask it to live next.

Sources

  1. Komtrax Quick Reference Guide — Komatsu

    Used for the fact that manufacturer telematics reporting distinguishes working hours from figures such as actual working hours, travel, digging and swing hours, and reports idling. Capability varies by machine and market.

  2. Undercarriage System Management Guide — Caterpillar

    Used for the manufacturer position that undercarriage wear depends on application, ground and material conditions, operating technique, track adjustment and cleaning practice rather than hours alone. Applies to undercarriage systems, not to machines generally.

  3. Cat Certified Rebuild — Caterpillar

    Used for the existence of defined manufacturer rebuild scopes, applied engineering updates and a new identification number for a rebuilt machine. One manufacturer's programme, not a general rule about rebuilds.

  4. Condition Monitoring — Caterpillar

    Used for the practice of interpreting electronic and telematics data, fluid analysis, inspections, service history and operating context together rather than in isolation. Presented as manufacturer practice, not as proof that failure can be predicted.

  5. ISO 15143-3 (AEMP Telematics Standard) — Association of Equipment Manufacturers

    Used for the existence and purpose of a standardised telematics data exchange specification for mixed fleets. A defined common field set does not make different manufacturers' data identical.

  6. Telematics and equipment monitoring — Komatsu

    Used for manufacturer support of standardised telematics data exchange as the route to mixed-fleet reporting.

  7. Development of an Automated Fleet-Level Equipment Replacement Methodology — Texas Department of Transportation / University of Texas at San Antonio, 2003

    Used for the finding that the trend of a unit's life-cycle cost history carries more replacement information than a fixed annualised cost threshold. Research developed for one public fleet, not a universal replacement model.