What is machine planning?

Machine planning refers to the scheduling of machines, plant, production lines and technical equipment in terms of time, capacity and organisation. Production orders are allocated to suitable machines and available time slots.

Structured machine planning does not merely take into account whether a machine is available. It also checks whether the machine is technically suitable for the job in question, how long the machining time will be, and whether tools, fixtures, programmes and qualified staff are available.

The aim is to fulfil production orders on time, make efficient use of machine capacity and reduce unnecessary downtime, waiting times and set-up times.

With a digital machine planning Machine utilisation, production orders, maintenance and technical resources can be coordinated within a single visual planning system.

What tasks are involved in machine planning?

The tasks involved in machine planning vary depending on the type of production, the machinery in use and the level of vertical integration. The most important areas include:

• Allocation of production orders to machines
• Machine utilisation planning
• Taking available machine capacities into account
• Testing of technical machine characteristics
• Planning of processing and lead times
• Taking set-up times into account
• Planning maintenance and inspections
• Coordination of tools and fixtures
• Allocation of qualified staff
• Prioritising urgent production orders
• Co-ordination of multiple production lines
• Responding to machine breakdowns and schedule changes
• Monitoring order progress and machine status

Machine planning becomes particularly challenging when several machines have different capabilities, orders go through various work stages, and limited tools or skilled staff are shared.

Which resources need to be taken into account in machine planning?

A machine can only be used productively if all the resources required for the job are available. That is why machine planning involves more than simply reserving a time slot.

Machinery and plant

Technical resources that can be scheduled may include:

• CNC machines
• Machining centres
• Milling machines
• Lathes
• Welding systems
• Laser cutting machines
• Press
• Injection moulding machines
• Printing presses
• Assembly lines
• Packaging systems
• Test benches
• Production lines

When selecting a machine, technical specifications and actual capacities must be taken into account.

Tools and equipment

Many orders require additional resources that are in limited supply:

• Clamping devices
• Moulds and tools
• Milling and turning tools
• Measuring equipment
• Test equipment
• Pallets
• Tool holders
• Assembly jigs
• Specialist tools

A machine may be available but still not be used if the required fixture is already in use on another job.

NC programmes and work documents

In automated processing procedures, the necessary programmes and documents must be available in good time. These include, for example:

• NC programmes
• Work plans
• Drawings
• Parts lists
• Checklist
• Set-up instructions
• Quality requirements
• Machine parameters

Missing or unapproved documentation may delay the planned start of production.

Staff and Qualifications

Qualified staff are required to operate, set up or monitor a machine. This includes, for example:

• Machine operator
• Fitter
• Programmer
• Toolmaker
• Maintenance technician
• Quality Assurer
• Production Manager
• Shift supervisor

When Staff deployment planning Shifts, qualifications, absences and already scheduled activities must be taken into account.

Materials and intermediate products

A production order can only commence once the required materials or semi-finished products are available and have been approved.

This may include:

• Raw materials
• Semi-finished products
• Components
• Consumables
• Packaging materials
• Consumables and operating supplies

A shortage of materials often means that reserved machine time cannot be utilised.

How does machine planning work?

Professional machine planning is carried out in several coordinated steps.

1. Create a production order

First, the order data relevant to planning is recorded. This may include:

• Order number
• Client
• Product or item
• Order quantity
• Desired delivery date
• Priority
• Estimated processing time
• Required steps

2. Determine the appropriate machine

The system then checks which machine is technically capable of processing the order.

Key criteria may include:

• Machine type
• Scope of work
• Service
• Machining accuracy
• Toolkit
• Production speed
• Material suitability
• Available programmes

Not every available machine is automatically suitable for every job.

3. Check machine capacity

Planning must take account of the capacity that is actually available. For example, a machine may only be available at certain times due to shift patterns, maintenance, technical limitations or a lack of operating staff.

What is therefore decisive is not the theoretical machine capacity, but the actual capacity during the respective planning period.

4. Schedule processing and set-up times

Before the actual machining can take place, a machine often needs to be set up or reconfigured.

Typical set-up operations include:

• Tool change
• Change of legal form
• Cleaning
• Change of material
• Programme change
• Set-up of clamping devices
• Calibration
• Trial run and initial partial check

Set-up times must be taken into account as a separate component of machine utilisation. Otherwise, the planned start of production will be unrealistic.

5. Allocate staff and resources

The required staff, tools, fixtures and test equipment are scheduled to coincide with machine operating times.

This prevents a job from being reserved on a machine but unable to be started due to a lack of additional resources.

6. Set the order of the orders

The order sequence affects delivery dates, set-up time and machine utilisation.

Possible prioritisation criteria include:

• Delivery date
• Order priority
• Client approval
• Material availability
• Set-up family
• Processing time
• subsequent production steps
• Availability of further resources

7. Monitor production progress

During production, checks are carried out to ensure that the order starts, progresses and is completed as planned.

Deviations may arise due to:

• Machine faults
• Quality issues
• missing material
• Staff absences
• extended processing times
• urgent additional orders

8. Update the plan when changes are made

In the event of faults or changes in priority, jobs must be rescheduled, redistributed to other machines or reprioritised.

A centralised planning view shows which subsequent orders, staff and delivery dates are affected by the change.

A practical example of machine planning

A metalworking company is planning several production orders across three CNC machining centres.

An urgent customer order needs to be squeezed in at short notice. Two machines would, in principle, be suitable for the component. However, one machine is out of action for maintenance. A job is currently running on the second machine, and its processing time is taking longer than planned.

In addition, a special clamping device is required for the new order, which is currently in use on a third machine.

With centralised machine planning, the production manager can see:

• which machines are technically suitable for the job
• when the required clamping device will be available
• which existing orders would need to be rescheduled
• which delivery dates are at risk as a result of the rescheduling
• which qualified machine operator is available
• whether an additional shift is required

The urgent order can be scheduled within a realistic timeframe without reserving a machine or piece of equipment that is unavailable.

The difference between machine planning and production planning

Machine planning and production planning are closely linked, but have different focuses.

Machine planning focuses primarily on:

• Allocation of individual machines and plant
• Machine capacities
• Set-up and processing times
• technical suitability
• Maintenance and faults
• Tools and equipment

The Production planning also includes:

• all production orders
• Material requirements
• Work sequences
• Staffing requirements
• Delivery dates
• Stock levels and intermediate products
• cross-functional manufacturing processes

Machine planning is therefore a key component of production planning.

The difference between machine planning and capacity planning

Capacity planning compares the expected capacity requirements with the available personnel and technical capacities.

Machine planning puts this capacity analysis into practice. It determines which job is to be carried out on which machine and at what time.

Example: Capacity planning shows that 180 machine hours are required in the coming week, but only 150 hours are available. Machine planning identifies which machines are causing the bottleneck and which jobs can be postponed or allocated to alternative machines.

The difference between machine planning and detailed planning

Detailed planning coordinates production orders in detail according to machines, resources and specific time slots.

Whilst high-level production planning often operates on a daily or weekly basis, detailed planning examines individual work steps, machine allocations and processing sequences in greater detail.

Detailed planning includes, for example:

• exact start and end times
• Order of individual orders
• Set-up time optimisation
• Taking dependencies into account
• Staff allocation
• Planning of limited tools
• Response to short-term deviations

Machine planning often forms the operational basis for this detailed planning.

Machine planning and resource planning

The Resource planning coordinates staff, machinery, tools, rooms and other operational resources.

Within this overarching resource planning framework, machine planning focuses on the technical production equipment and its allocation.

Example: Machine planning shows that a milling machine is available on Tuesday. Resource planning also checks whether an operator, the required fixture and the appropriate measuring instrument are also available.

Machine planning and staff scheduling

A machine can only be used productively if there are sufficient numbers of qualified staff available.

When planning jointly, the following factors, amongst others, must be taken into account:

• Shift models
• Qualifications
• Machine training
• Absences
• Breaks and working hours
• Multi-machine operation
• Developers and programmers
• Maintenance staff

A machine may be technically available, but still cannot be scheduled due to a lack of operating staff.

Machine planning and maintenance planning

Maintenance and inspections must be taken into account as fixed downtime periods in machine allocation.

Schedulable maintenance tasks include:

• regular inspections
• preventive maintenance
• Tool change
• Cleaning
• Calibration
• Security checks
• Software updates
• Repairs
• unplanned fault rectification

Co-ordinated maintenance planning reduces unplanned downtime and prevents production orders from being scheduled during a planned machine shutdown.

Machine planning and shop floor management

The Shop floor management provides transparency regarding ongoing production processes directly at the point of value creation.

Machine planning provides important information for this:

• which job is running on which machine
• which jobs are next
• where delays occur
• which machine is faulty
• which order needs to be prioritised
• which capacities are available

Planning and shop floor management complement each other. Machine planning determines the scheduled utilisation. Shop floor management provides a clear overview of the current production status and any deviations.

Machine planning and project planning

Machines are not only used for production runs or individual orders. They can also form part of larger projects.

The Project planning coordinates a project’s tasks, deadlines, milestones and resources. Machine planning ensures that the required equipment is available during the designated project phases.

This is relevant, for example, in the following cases:

• Prototype manufacturing
• Toolmaking
• Special-purpose machinery manufacturing
• Series of experiments
• Research and development projects
• customised single-item production

Set-up times in machine planning

Set-up times are periods during which a machine is prepared for a new job. During this time, the machine does not produce any saleable parts.

Set-up times can arise due to:

• Tool change
• Change of legal form
• Cleaning
• Change of material
• Changing machine parameters
• Construction of fixtures
• Programme change
• Initial review

A sensible sequence of orders can reduce set-up times. For example, if similar products or materials are manufactured one after the other, fewer and less extensive changeovers are required.

However, reducing set-up times must not be viewed in isolation. Delivery dates and order priorities must still be met.

Machine capabilities and plausibility checks

When assigning machines, it is necessary to check whether a machine is technically capable of carrying out the intended job.

Possible machine capabilities and limitations include:

• maximum workpiece size
• permissible workpiece weight
• Machining accuracy
• materials that can be processed
• Available tools
• Spindle power
• Production speed
• Temperature or cleanroom requirements
• Required certifications
• available workspace

A plausibility check prevents jobs from being scheduled on unsuitable machines.

Parallel and multi-stage machine allocation

Many production orders go through several stages of processing on different machines.

For example, a component may require the following stages:

1. Cutting
2. Milling
3. Drilling
4. Surface treatment
5. Quality check
6. Assembly

The planning must ensure that subsequent operations do not begin until the previous step has been completed.

Several machines can work on different jobs simultaneously. This creates dependencies that are difficult to identify in a simple list of machines.

Common mistakes in machine planning

Only the theoretical capacity is taken into account

Shift times, maintenance, faults, breaks or a shortage of operating staff are not taken into account.

Set-up times are missing

Jobs are scheduled back-to-back without allowing time for tool changes, cleaning or set-up.

Machine capabilities are not tested

An order is placed on an available machine that is, however, technically unsuitable.

Tools and fixtures are being used twice

Several machines require the same limited resource at the same time.

Maintenance appointments are overlooked

A production order is scheduled during a planned inspection or repair.

Staff availability is planned separately

The machine is available, but there is no qualified operator or set-up technician on hand.

Material availability is not taken into account

Machine time is reserved even though the required raw materials have not yet arrived or been released.

Dependencies between work steps are missing

A follow-up order is being scheduled, even though the required intermediate product has not yet been completed.

Disruptions are not communicated centrally

Production planning, manufacturing and sales departments work with different information regarding machine status and delivery dates.

Key performance indicators for machine planning

Machine utilisation

Machine utilisation shows the extent to which available machine time is being used productively.

Machine availability

Machine availability describes the proportion of the scheduled time during which a machine is actually operational.

Downtime

Downtime refers to periods during which a machine is not in production due to faults, maintenance, a lack of materials or a shortage of staff.

Set-up time

Set-up time indicates how much time is required to prepare a machine between two production orders.

Processing time

The machining time describes the actual duration of the machining process for a job or component.

Lead time

Lead time refers to the period from the start of an order to the completion of all necessary processing steps.

On-time delivery

On-time delivery shows how often production orders are completed within the planned timeframe.

Failure rate

The downtime rate compares unplanned stoppages or downtime to the available machine time.

Maintenance rate

The maintenance rate shows what proportion of the available time is used for planned maintenance and servicing measures.

Capacity utilisation

Capacity utilisation compares the scheduled machine requirements with the actual available machine capacity.

Order backlog

The order backlog shows which production orders were not processed within the planned timeframe.

Software as a support tool

Software can support machine planning by providing centralised information on deadlines, availability, resources and responsibilities. The most suitable solution depends on the specific process, the available data and the existing systems. One example is Machine planning with Visual Planning®.

Conclusion

Structured machine planning links machines, production orders, tools, maintenance, staff and delivery dates to form a realistic utilisation plan. It helps to identify capacity bottlenecks at an early stage and to take dependencies between production steps into account in a transparent manner.