Equipment downtime causes are classified in two layers
Equipment downtime causes are first split into five main classes and then into a small number of cause codes under each class. The main classes are planned, unplanned, standby, external factor and logistics; the main class tells you who is responsible for the stoppage, and the cause code tells you what to do.
Example: an excavator stood idle for three days. If the record says only stopped, no decision comes out of it. If the cause is a breakdown, the matter belongs to the workshop and it lowers availability; if there was no work, the question is one of planning; if it was the weather, nobody is responsible, but you check whether the rental contract has a clause for it. The same three-day record goes to three different desks.
Why classification is needed
Four decisions come out of the same downtime data. Availability is calculated from the downtime hours; for a rental deduction, the day status the stoppage falls under is decisive; a breakdown-related stoppage is tied to repair cost; and for responsibility, who recorded it and in which class matters. If the causes get mixed up, all four decisions are spoiled together: a breakdown recorded as standby does not enter the fault count and repair time, makes MTBF look better than it is and ties the rental deduction to the wrong day; a lack of work recorded as a breakdown, on the other hand, inflates the workshop's repair time.
How the days translate into rent, that is, which day status is billed or deducted from the rent, is explained in the rented equipment billing guide. The subject here is recording the input of that calculation, the stoppage itself, cleanly.
The five main classes and who is responsible for them
Each class has a different owner. This distinction makes sure the right person speaks in the weekly meeting.
- Planned: maintenance and overhauls scheduled in advance. The maintenance lead or the workshop manager is responsible; the aim is to announce the stoppage beforehand and keep it short.
- Unplanned: breakdowns and accidents. The equipment manager and the workshop are responsible; the aim is to reduce the frequency and the duration.
- Standby: the machine is sound, but there is no work or no operator. The foreman and the site manager are responsible; this is a planning question.
- External factor: weather, public holidays, leave or a local ban. The site manager records it; it cannot be influenced, but its counterpart in the contract is checked.
- Logistics: transport and the materials for the job not arriving. Dispatch and purchasing are responsible.
How the downtime types in the product fit this scheme
The product has five downtime types: unplanned (breakdown), planned (maintenance), standby, transport and accident. The mapping is direct: breakdown and accident fall under the unplanned main class, maintenance under planned, standby under standby, and transport under logistics. For weather and holidays, the timesheet day statuses (Weather delay, Holiday) are used; for distinctions such as no work and no operator, the company can add its own day status. In fault records, the fault category defined by the company is mandatory; the cause codes of the unplanned class are to a large extent this list.
Sample code list
The list below is a starting draft; each example in a row is an assumption. The company shortens it to suit its own sites.
Sample list for downtime codes
| Class | Cause | Example | Who records it | Which indicator it enters |
|---|---|---|---|---|
| Planned | Periodic maintenance | Machine taken to the workshop for the 500-hour service | Maintenance lead, with a work order | Availability downtime; outside MTTR |
| Planned | Planned repair | Track undercarriage replacement planned in advance | Equipment manager | Availability downtime; maintenance cost |
| Unplanned | Breakdown (with a category such as hydraulic, electrical or engine) | Boom hose burst | Opened by the operator or foreman; closed when the workshop gets the machine running again | MTBF, MTTR, availability; fault repair cost |
| Unplanned | Accident | Machine cannot operate after a collision | Site manager, with an accident record | Availability; rental deduction depends on fault; compensation and insurance amounts do not enter cost |
| Unplanned | Waiting for parts (within an open fault) | Waiting for a spare hydraulic pump | Same fault record | Not shown separately, it is included in MTTR; the stoppage lasts until the machine is running again |
| Standby | No work | Machine idle because the excavation area is not ready | Foreman | Availability downtime; in utilisation it is removed from the denominator according to the approved timesheet status |
| Standby | No operator | The shift operator did not show up, no replacement was assigned | Foreman | Availability downtime; read together with the operator assignment record |
| External factor | Weather delay | Work stopped because of heavy rain | Site manager, by correcting the timesheet draft | Timesheet day; the deduct-from-rent flag follows the contract |
| External factor | Public holiday | No work done on a holiday | Site manager | Timesheet day; the rental decision follows the holiday clause of the contract |
| Logistics | Transport | Machine is being moved to site B on a low-bed trailer | Dispatch officer; a transport stoppage is opened at dispatch | Transport stoppage; rental effect depends on who is responsible for dispatch |
| Logistics | Waiting for materials | Sound machine idle because the breaker tool did not arrive | Foreman | Availability downtime (standby); read together with the dates of the purchasing record |
| Unclear (temporary) | Cause not entered | Stoppage open, cause empty | Closed by the site manager | Not reliable for any decision; must be cleared before month end |
Recording flow: who, when, which record
The flow starts the record with the person at the machine and collects it with the site manager at the end of the day. In Reper Axis, fault, accident and dispatch records start the stoppage automatically; for the remaining cases, the person authorised to enter stoppages records it manually.
- The operator or foreman opens the fault with the machine cannot operate flag; the stoppage starts automatically. It closes when the machine is marked as running.
- If the machine cannot operate in an accident record, an accident stoppage is opened; in a dispatch record, a transport stoppage is opened.
- Standby cases such as no work, no operator and the like are entered as a manual stoppage by the person given the authority to enter stoppages, on most sites the foreman.
- For each day, the system generates the daily timesheet draft from the meter, stoppages, dispatch and operator assignment; the site manager corrects and approves it (with the machine timesheet module).
- At the end of the week the downtime breakdown is brought to the meeting; when the month ends, the timesheet is locked.
How a fault becomes a downtime record: a sample timeline
Example: on Tuesday morning at 09:40 a boom hose burst. The foreman opens the record with the fault category hydraulic and the machine cannot operate flag; the stoppage starts at that minute. Towards noon the order for the spare hose is placed and the record stays the same: the time spent waiting for the part is not a separate stoppage, it is inside the open fault. On Wednesday at 14:20 the workshop fits the hose and marks the machine as running, and the stoppage closes.
The result is a single unplanned stoppage of 28 hours 40 minutes; the main class is unplanned, the cause is hydraulic fault, and the recorder is the foreman and the workshop. In the weekly meeting this record enters both the fault count and the downtime. The parts waiting time is not shown separately; it is included in the unplanned stoppage of the open fault and in the MTTR calculation. A company that wants to track this time separately reads it from the dates of the purchasing record.
Recording rules: the company makes the decision
All of the rules below are decisions the company makes. The software does not impose them; when they are not written down, each site applies its own rule and the sites cannot be compared with one another.
- Start and end times are recorded at the actual moment. A time written afterwards from memory makes the repair time look short and availability look high; for the definition of the measures, see the MTBF and MTTR guide.
- Single dominant cause: if two causes exist at the same time, the record is written against one cause. Sample rule: ask whether the machine could have operated if that cause went away at that moment. Even if the rain stops, if the machine cannot operate because the hose has burst, the cause is the breakdown.
- For unclear records, set a person responsible for closing them and a deadline. For example, the site manager closes unclear stoppages before the month is locked.
- Short-stoppage threshold: as an example, stoppages shorter than 10 minutes can be passed without opening a record. If the threshold is low, record fatigue appears; if it is high, frequent small stoppages become invisible.
- Overlapping stoppages are not counted twice; a single record remains for the same machine in the same time range.
- The code list is reviewed once a year; changing a code in the middle of a month breaks the comparison.
A sample week of downtime breakdown
The figures below are an example: say a group of five machines has recorded a total of 120 hours of downtime in a week.
Downtime breakdown for a sample week (Pareto order, figures are assumptions)
| Main class and cause | Downtime hours | Share | Cumulative share |
|---|---|---|---|
| Unplanned: breakdown (hydraulic) | 34 | 28.3% | 28.3% |
| Standby: no work | 26 | 21.7% | 50.0% |
| External factor: weather | 22 | 18.3% | 68.3% |
| Planned: maintenance | 16 | 13.3% | 81.7% |
| Logistics: transport | 10 | 8.3% | 90.0% |
| Standby: no operator | 7 | 5.8% | 95.8% |
| Unclear | 5 | 4.2% | 100.0% |
Reading the Pareto: the same number, different desks
The first two items are half of the week, but they do not go to the same desk: the 34 hours of breakdown are the workshop's subject, the 26 hours of no work are planning's. Weather is third with 22 hours and cannot be managed; the only question asked of it is its counterpart in the contract. The items the company can influence (breakdown, no work, no operator, unclear) come to 72 hours, that is, 60 percent. The 5 unclear hours look small, but they must be brought down to zero, because nobody owns those hours.
Downtime, MTBF and MTTR are shown by machine and by machine group in the availability report. If the share of breakdowns grows, the next step is to separate the recurring causes; for the method, see the root cause analysis guide.
Keeping the code list from bloating
When the scheme gets messy, the first reflex is to add more codes; yet a list of 40 codes is not used in the field, and the foreman picks the first code that looks reasonable. A single test is enough for every new code: in the weekly meeting, do these two codes lead to a different decision? If they do not, they are merged into one code. The same rule applies to the fault category: if hydraulic leak and oil leak are written separately, the Pareto is split.
When you are stuck, look at the main class. If the main class is right, the responsibility decision usually comes out right even when the cause code is wrong; if the main class is wrong, even the best cause code goes to the wrong desk.
