Quality control

An inspection plan is prepared before the first series starts, based on the critical dimensions in the drawing rather than a generic checklist. Together with the customer we identify which dimensions matter functionally, which are difficult to hold in production, and which need particular attention because of the material's properties. That prioritisation makes inspection targeted rather than time-consuming without reason.

The inspection plan sets out which equipment is used for each dimension, how often it is measured, and which tolerance limits trigger action. Critical dimensions are measured on every part or at a fixed frequency in large series, while less critical dimensions can be sample-checked. The plan is documented in writing and updated if the drawing or process changes.

For new parts, an initial full-sample measurement is carried out, often called an initial process evaluation, where every critical dimension is checked on every part. That shows whether the process is stable enough to move to the agreed, less intensive inspection plan, or whether adjustments are needed before the series is released to normal running.

Statistical process control is used in series where it makes sense to follow a process over time rather than just judge the individual part. Measurements are plotted continuously on control charts showing whether the process sits stably around the target, or whether trends point towards the tolerance limit. A trend is typically caught long before a part actually falls out of tolerance.

When a control chart shows a systematic deviation, for example due to tool wear or a temperature change in the production area, the process is adjusted immediately. That is cheaper and faster than waiting for a part to fail final inspection, and it means the customer rarely experiences variation in a standing series, even over a long period.

Data from statistical process control can be made available to the customer as part of ongoing documentation, often as periodic reports showing the process's capability. For customers with their own capability requirements, for example specific Cpk values, we agree specifically how this is documented and reported.

Our own suppliers, of material, standard components and surface treatment, are part of the quality system in the same way as our internal processes. New suppliers are approved based on technical assessment and trial deliveries, and existing suppliers are followed continuously on delivery accuracy, quality and response to deviations. A supplier who fails to meet the standard over time is replaced.

Incoming material is checked on receipt against what was ordered and against the accompanying certificate before it is released for production. For critical materials, certificate information is spot-checked against our own measurements, so we do not rely solely on the supplier's documentation when the material is going into a critical component.

Components purchased for assembly undergo a corresponding incoming inspection tailored to the component type, from visual inspection of surfaces to functional testing of mechanical parts. The result is recorded on the production order, so a defective purchased component can be traced back to the specific batch if it causes problems later in the assembly.

The quality system is not static. Deviations, customer feedback, internal audits and management review are actively used to find improvements, both in production and in the quality work itself. A process that has run stably for several years is still reassessed at regular intervals, because materials, tooling and requirements change over time.

Internal audits are carried out systematically across departments to verify that procedures are followed in practice, not only on paper. Results are used to adjust instructions, training and equipment, and recurring findings across audits are treated as an indication of a structural problem that requires more than a single correction.

Management review of the quality system takes place regularly with the involvement of those responsible in production, not the quality function in isolation. That ensures decisions on investment, training and process changes are based on the actual deviations and trends seen in production, not only on overarching objectives.