Know-How

Maintenance Plan: Definition, structure, intervals, examples & optimization with CMMS

Picture of <div class="post-authorline"> <span class="author-name">Daniel Mirbach</span>, <span class="author-role">Head of Marketing</span>

Daniel Mirbach, Head of Marketing

What is a maintenance plan?

A maintenance plan defines which maintenance tasks are carried out on a piece of equipment, when, to what extent, and under what conditions. The maintenance plan thus provides a structured basis for the planned maintenance of machines, systems, buildings, vehicles, and other tangible assets of a company.

Within maintenance overall, which includes not only servicing but also inspection and repair, the maintenance plan focuses on all maintenance measures to be planned, their execution, and documentation. For example, it describes when and by whom lubricants are to be changed, filters cleaned, wear parts checked, or specific components serviced on a regular basis.

Why is a maintenance plan important for machines and other assets?

A well-structured maintenance plan supports six objectives:

Reducing unplanned downtime
Increasing equipment availability
Predictable maintenance costs
Economical operation of machines and other assets
Ensuring operational safety
Making maintenance performance measurable

Reducing unplanned downtime

Regular maintenance helps identify wear and issues early and address them as effectively as possible. This helps avoid unplanned failures or at least makes them more predictable. A maintenance plan cannot prevent unplanned faults entirely, but it ensures that known, plannable maintenance tasks don’t themselves become a trigger for avoidable failures. This is especially relevant for critical equipment whose failure directly affects production or other operational processes.

Increasing equipment availability

The availability of a piece of equipment doesn’t depend solely on how often it fails. The duration of unplanned downtime also plays an important role. This is where metrics such as MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) come into play. A structured maintenance plan focuses primarily on prevention: recurring maintenance tasks are defined and scheduled in advance. The actual development of the equipment can then be assessed based on maintenance and fault data, for example, whether a piece of equipment keeps failing despite regular maintenance, or whether certain maintenance tasks are particularly prone to deviations.

Planning maintenance costs

Maintenance is an investment in availability and operational safety. The necessary resources like labor, spare parts, consumables, and external service providers need to be planned accordingly. A maintenance plan makes the following visible early on:

which maintenance tasks are coming up,
which employees are needed for them,
which spare parts or materials are required,
how much working time needs to be scheduled, and
which external service providers, if any, need to be involved.

This turns maintenance from a largely reactive activity into a predictable maintenance task, making any costs that arise visible and calculable at an early stage.

Economical operation of machines and other assets

Wear is unavoidable for many assets. Regular maintenance makes it possible to identify signs of wear early and initiate appropriate measures. A maintenance plan helps ensure these recurring tasks don’t depend on individual employees’ memory. At the same time, documented maintenance creates a history from which long-term insights into an asset’s condition and behavior can be derived.

Ensuring the safety of work equipment

Maintenance isn’t just a matter of availability and cost. It’s also connected to the safe use of work equipment. In many countries, companies are legally required to keep work equipment in a safe condition throughout its entire service life taking into account manufacturer specifications and a risk assessment.

In Germany, for example, this is regulated by the Ordinance on Industrial Safety and Health (Betriebssicherheitsverordnung, BetrSichV), which defines maintenance as “… the entirety of all measures for preserving a safe condition or restoring it” and explicitly names inspection, servicing, and repair as its components. In addition, the regulation of Germany’s social accident insurance system (Deutsche Gesetzliche Unfallversicherung, DGUV) contains specific requirements and guidance for inspecting and documenting work equipment. Depending on the equipment, inspection reports may be required.

A maintenance plan can therefore organize not only planned maintenance work but also inspection deadlines and required inspection tasks. While maintenance aims to preserve a safe condition, an inspection serves to determine and assess an asset’s current condition.

Making maintenance performance measurable

A maintenance plan makes the work actually performed measurable and assessable using suitable metrics. Depending on the company, the following metrics may be relevant:

Maintenance backlog: which planned maintenance tasks have not yet been carried out?
On-time completion: how many maintenance tasks were completed on schedule?
MTBF: on average, how long does a piece of equipment run between two failures?
MTTR: how long does it take to restore equipment after a failure?
Maintenance cost per asset: what costs are incurred for maintaining a given asset?
Equipment availability: how much of the scheduled operating time is the equipment actually available?
Overall Equipment Effectiveness (OEE): how effectively is the available operating time actually used?

No single metric should be viewed in isolation. Since equipment availability is one of three OEE factors, a well-tuned maintenance plan has a direct impact on OEE. A high rate of on-time completed maintenance, for example, says nothing on its own about whether the chosen maintenance intervals are actually appropriate. Only the combination of planning, execution, and the resulting operational and fault data allows for a well-founded assessment.

What maintenance intervals and triggers are there?

Not every maintenance task follows a fixed time interval. Depending on the asset, the maintenance task, and the operating conditions, different triggers can make sense. The maintenance interval defines when a maintenance task is scheduled to be carried out.

In practice, the following intervals or triggers are particularly common:

With a calendar-based interval, maintenance is carried out at a fixed time interval such as daily, weekly, monthly, semi-annually, or annually.

One example is the annual maintenance of an air conditioning system, or the monthly inspection of a filter.

This approach is particularly suitable for maintenance tasks where the passage of time has a significant influence on maintenance needs.

An alternative scheduling approach is completion-based scheduling. The next maintenance date is calculated based on the actual completion of the previous maintenance task. If maintenance is carried out late, for example, the next scheduled date is shifted accordingly.

Operating-hour-based maintenance intervals

For machines and equipment, it’s often not the elapsed time but the actual usage duration that matters. The interval is then tied to operating hours.

Example: an oil change every 2,000 operating hours.

A machine that runs around the clock reaches this interval faster than the same model used only a few hours per week.

Usage- and cycle-based maintenance intervals

The actual usage of an asset can also serve as a trigger. Maintenance can, for example, be scheduled after a certain number of production cycles, workpieces, switching operations, operating cycles, or kilometers driven.

This is particularly useful when wear depends more on usage than on elapsed calendar time.

Condition-based maintenance intervals

With a condition-based interval, maintenance needs are determined by the actual condition of an asset or component. Instead of replacing a component every six months on a fixed schedule, its condition is monitored. Once a defined threshold is approached, maintenance action is triggered. Possible condition indicators include temperature, vibration, pressure, wear, or oil quality. In this case, there is no rigid interval in the classic sense. The condition of the asset determines when maintenance takes place.

Predictive maintenance intervals

Predictive maintenance goes a step further. Here, condition data and historical information are used to forecast future maintenance needs. The timing is no longer derived solely from a fixed interval, but from a prediction of the expected condition or point of failure, typically using a condition monitoring system.

Run-to-failure: Maintenance only when needed

Not every asset requires one of the intervals described above. With the run-to-failure approach, a component is deliberately operated until it fails. Only when a fault occurs or the component no longer functions is it repaired or replaced.

Run-to-failure is therefore not a maintenance interval in the strict sense, but a reactive maintenance approach. It can make sense for low-criticality, inexpensively replaceable components.

Which maintenance interval makes sense depends on several factors. The starting point is usually the manufacturer’s specifications. Actual operating conditions also play a role: a machine operated under heavy load, high temperatures, or in a dusty environment may have different maintenance needs than the same model under less demanding conditions.

The criticality of an asset also matters. For a machine whose failure would cause significant production downtime, closer monitoring or more frequent maintenance may be appropriate.

Additional factors beyond manufacturer specifications, operating conditions, and criticality include:

operating hours and usage intensity
wear behavior of components
past faults and maintenance outcomes
cost of maintenance versus unplanned downtime
requirements from risk assessments
legal and internal requirements

What belongs in a machine maintenance plan?

A machine maintenance plan describes, as specifically as possible, which maintenance tasks are performed on a machine, when they are due, and who is responsible. To ensure tasks can be reliably planned and carried out, the plan should include, alongside intervals, all information relevant to execution.

The exact details required depend on the machine, its use, and the maintenance strategy in question. Typical components include:

Clearly identify machines and other equipment

It must first be clear which asset the plan applies to. This includes, for example:

machine or system designation
inventory or asset number
location
assembly or component
manufacturer and model
serial number, if applicable

Clear identification is especially important for larger machine fleets, so it can later be traced which maintenance was carried out on which asset.

Maintenance tasks and work steps

The plan should define what needs to be done during each maintenance task. This includes activities such as:

checking and lubricating grease points
inspecting or replacing filters
checking wear parts
checking screw and clamp connections
checking fluid levels
checking safety-relevant components
performing cleaning tasks

For more complex tasks, additional work instructions, checklists, or manufacturer specifications can be attached, turning a general note into a clear, actionable basis for whoever carries out the work.

Maintenance interval and due date

A key component is the maintenance interval, or trigger, for the next maintenance task. It should also be clear when the next maintenance is due. For recurring maintenance, this creates an ongoing maintenance plan.

Responsibilities and required resources

For maintenance to be not just planned but actually carried out, responsibilities should be clearly assigned to the person responsible, the maintenance team, or an external service provider.

Depending on the task, additional resources can also be defined, such as:

estimated working time
required qualifications
spare and wear parts
tools and equipment
required machine or system downtime
external service providers

This makes preparation easier and helps integrate maintenance work into existing capacity and production planning.

Documentation and maintenance history

A complete maintenance process also includes documenting the work actually carried out in detail:

date performed
duration
person who carried it out
work performed
deviations or damage identified
parts replaced
measured values and test results
notes for the next maintenance task

This information also forms the asset’s maintenance history as a basis for identifying recurring issues and adjusting maintenance plans in a targeted way later on.

Key components at a glance

A machine maintenance plan should answer at least the following questions:

Question	Typical information
What is being maintained?	Machine, system, assembly, component
What needs to be done?	ReaktionszeitWartungsaufgabenMaintenance tasks, checklist, work instructions
When is maintenance due?	Interval, operating hours, cycles, condition value
Who carries it out?	Employee, team, external service provider
What is needed?	Spare parts, tools, materials, working time
What was found?	Results, deviations, measured values, damage
What was done?	Work completed and components replaced

A good maintenance plan connects the asset, maintenance task, interval, responsibility, and documentation.

Example of a machine maintenance plan

Machine	Maintenance task	Interval	Responsible	Documentation
Production Machine A	Check lubrication points	4 weeks	Maintenance	Checklist
Production Machine A	Replace filter	2,000 operating hours	Maintenance	Maintenance order
Conveyor System B	Check bearings	3 months	Maintenance	Maintenance report
Pump C	Monitor condition	continuous	Maintenance	Condition data

Maintenance plan, Maintenance order, and work order: What's the difference?

Maintenance plan, maintenance order, and work order are frequently used terms in maintenance that are sometimes defined differently. The maintenance plan defines the “what” and “when.” The maintenance order specifies a single, due maintenance task. The work order is the overarching term for any concrete work task.

Maintenance order: Carrying out a specific maintenance task

When maintenance becomes due, a specific maintenance order is generated from the maintenance plan. It refers to a particular task at a particular time and contains the information needed to carry it out.

For example, a maintenance plan for a production machine could generate: Machine M-102 – check bearings every 500 hours – due October 15.

The order can also include the tasks to be performed, checklists, required spare parts, the responsible person, and other information. After completion, what was actually done and found is documented.

Work order: The overarching term

A work order generally describes a specific work task to be carried out by a person or a team. It can originate from a maintenance plan, but doesn’t have to. Besides planned maintenance, the following can also be recorded as a work order:

Not every work order is a maintenance order. A maintenance order is a specific type of work order tied to planned maintenance.

In simplified terms:

Maintenance plan → due maintenance → maintenance order → execution and documentation

For a fault, the process can look different:

Fault report → work order → troubleshooting → documentation

Such a work order doesn’t originate from a maintenance plan, but from a specific need.

What challenges arise in maintenance planning?

The larger the machine base and the more maintenance tasks accumulate, the harder it becomes to keep track of schedules, responsibilities, and maintenance information. With manual planning in particular, changes, rescheduling, and new insights must be continuously maintained.

Excel can be a practical starting point for smaller shopfloors and manageable plans. As complexity increases, however, several limitations become apparent:

No central version control for the currently valid maintenance plan
No automatic scheduling
No mobile access
Static planning
No feedback loop from faults
Limited traceability

Once many assets, recurring tasks, and different responsibilities come together, a structured digital solution becomes increasingly relevant. How maintenance planning can be mapped with dedicated software, such as Maintastic, and which features support this, is covered in detail in the article Maintenance Planning and Scheduling Software: Excel or Maintastic? A Guide for Small and Medium-Sized Businesses.

How a CMMS supports maintenance scheduling and documentation of a maintenance plan

A CMMS (Computerized Maintenance Management System) helps create and manage maintenance plans centrally and link them to actual execution. This allows recurring maintenance tasks to be not only planned, but also scheduled, assigned, and documented.

A digital maintenance plan can, for example, specify that a defined task be carried out weekly on a particular machine. The CMMS can then automatically generate the corresponding maintenance orders and assign them to the responsible employees. Depending on the system, working time, required spare parts, checklists, or work instructions can also be factored in.

Maintaining Maintenance plans centrally

When machines, responsibilities, or intervals change, the relevant information can be updated directly in the system, so the current version of the plan is always available centrally.

The maintenance history, part of asset management within a CMMS, stays linked to the respective asset. Maintenance carried out, defects identified, components replaced, and other information can be traced later.

Automatically scheduling maintenance

A CMMS can automatically account for recurring maintenance based on defined intervals through a built-in maintenance planning feature. Different triggers such as calendar intervals, operating hours, or other usage values can be used.

This reduces manual scheduling effort and helps keep due maintenance in view, while factoring in responsible parties and available capacity.

Condition monitoring and data-driven maintenance planning

A CMMS can connect different data sources with the maintenance process via interfaces. Condition monitoring systems provide condition data that can be used to identify, for example, increasing wear or unusual asset conditions. MES systems, on the other hand, can provide operational and production data such as operating hours, cycles, or quantities produced, which can serve as a basis for usage-based maintenance.

Such data can automatically trigger a notification, or a work order in the form of a ticket can be generated automatically. This allows interval-based maintenance to be combined with condition- and usage-based approaches and centrally incorporated into maintenance planning.

With Predictive Maintenance, condition data and historical information are used to predict when maintenance may be required. Prescriptive Maintenance goes one step further by deriving specific recommendations or actions from this information. For more complex tasks, additional Digital Work Instructions and documented maintenance and failure histories can help structure and implement the appropriate response.

Documenting maintenance work directly during execution

Planning doesn’t end once a maintenance order is created; feedback after execution is just as important.

Using a CMMS app, maintenance staff can process tasks directly at the machine, work through checklists, and document results. Deviations or damage can be recorded immediately and, if needed, converted into further maintenance actions.

This creates a seamless connection between the maintenance plan, maintenance order, execution, and maintenance history.

A closed loop for maintenance planning

The key advantage of a CMMS lies not only in digitally storing a maintenance plan. It connects planning with the subsequent maintenance processes:

A defined interval leads to a specific task. That task is carried out, documented, and feeds into the machine’s maintenance history. The insights gained can, in turn, be used to review and adjust tasks and intervals going forward.

A CMMS thus supports a closed loop from planning through execution to documentation and optimization.

Learn more about the structure, features, and use cases of a CMMS in the article What Is a CMMS? Definition, Features, Benefits, AI, and Use in Maintenance.

Optimizing maintenance plans

A maintenance plan should not remain unchanged indefinitely. Documentation of past maintenance, faults, and identified conditions provides valuable insight into whether existing tasks and intervals still match the asset’s actual needs.

A CMMS can link this information centrally with all assets and their maintenance history, creating a data foundation from which plans can be deliberately refined.

Regularly reviewing maintenance intervals

A maintenance interval set once doesn’t have to stay unchanged forever. Experience from completed maintenance and past faults can show that an interval needs adjusting.

If a component shows little wear over an extended period despite regular maintenance, it may be worth reviewing whether the current interval is still appropriate. Conversely, if failures keep occurring between two maintenance tasks, adjusting the interval or switching to condition-based monitoring may make sense.

Using maintenance history for decisions

The maintenance history shows what has actually happened to an asset. Recurring damage, frequently replaced components, or regularly identified wear can indicate that a task needs adjusting.

Conversely, consistently unremarkable maintenance results can be reason to question the current maintenance effort. The goal isn’t to reduce maintenance across the board, but to align the maintenance strategy with actual experience.

Incorporating condition Data

If condition data from a condition monitoring system is also available, it can be used to further develop maintenance plans. If measured values show that a component’s condition changes depending on actual usage, a purely time-based interval can be supplemented or replaced with condition-based maintenance. This allows plans to gradually evolve from rigid intervals toward more demand-driven maintenance.

Adjusting maintenance tasks in a targeted way

It’s not just intervals that can be optimized. The content of maintenance tasks should also be reviewed regularly:

Which work steps are actually relevant?
Which components show recurring wear?
Which spare parts are needed regularly?
Which tasks show recurring anomalies?
Which tasks could be triggered more precisely using condition data?
Where can checklists or work instructions be made more precise?

This allows the maintenance plan to be adjusted step by step to the asset’s actual requirements.

Conclusion: Systematically creating and developing maintenance plans

Systematically planning maintenance work, carrying it out on time, and documenting it in a traceable way are the primary purposes of a maintenance plan. It defines what is to be maintained on a machine, a system, or another asset, when maintenance is due, and what resources and responsibilities are required.

Maintenance intervals and tasks should be based on usage, operating conditions, criticality, and actual experience. What matters, therefore, is not treating the maintenance plan as a table created once, but as a living tool for maintenance management. Consistently evaluating maintenance results, faults, and condition data allows maintenance planning to be continuously refined.

A digital maintenance plan, or a CMMS, can support this process from planning and scheduling through execution and documentation to the later refinement of the maintenance strategy.