Training on inspection process capability according to VDA 5 & ISO 22514-7
As the old saying goes: “You can only manufacture as accurately as you can measure!” This means that the measurement uncertainty of the measurement and inspection process must be known for each measured value in order to be able to assess the measured value in relation to the specification limits. VDA Volume 5 and ISO 22514-7 describe how to determine measurement uncertainty and this approach also serves as a proof of capability. In addition, VDA 5 explains how inspection process management should function for a holistic approach.
In this VDA 5 training course, we will illustrate both key areas relating to process capability. To a large extent, we use software programs and demonstrate the application of the procedures using practical examples. This training focuses on quality management based on VDA Volume 5. This guideline is applied in manufacturing companies from the automotive industry, among others.
Training on inspection process capability according to VDA 5 & ISO 22514-7 in detail
Day 1 "Capability Analysis"
- Notes on GUM requirements
(Guide to the Expression of Uncertainty in Measurement) - Determining the influence quantities
- Visualising the Ishikawa diagram
- Calculating the standard uncertainty components for the measuring system
- Calculating the standard uncertainty components for the measurement process
- Calculating the expanded measurement uncertainty and capability indices QMS, QMP (process capability)
- Stability analysis and conformity assessment
Day 2 "Inspection process management"
- Terms and definitions
- Selecting suitable measuring devices or measuring equipment on the basis of test plans
- Risk assessment and decision criteria
- Optimization and transferability to similar measurement processes
- Dashboard for status overview
- Description of roles in inspection process management
Further information
What does inspection process capability mean?
In quality management, there are various standards relating to inspection process management, measurement uncertainty and proof of capability.
Inspection process capability according to VDA Volume 5 means that an inspection process is suitable for achieving an inspection decision under defined conditions. Capability is assessed on the basis of capability indices. These capability indices provide information on whether an inspection process is capable of performing the required test task with sufficient accuracy and repeatability.
In many cases, an inspection process is required to be capable and stable. To meet this requirement, its location and variation must remain constant over time, i.e. there must be no trends or systematic changes.
The ComPro VDA 5 training course teaches you the relevant fundamentals, methods and practical implementation of capability analyses in industrial manufacturing.
How are inspection process capability and measurement uncertainty related?
Inspection process capability means that an inspection process is capable of providing reliable and reproducible results and thus distinguishing between good and bad parts. Normally, this is demonstrated by calculating capability indices. However, measurement uncertainty is becoming increasingly important as it is used as an alternative or supplementary method for demonstrating the capability of an inspection process. But why is this the case?
Measurement uncertainty considers all relevant influence quantities (e.g. repeatability, reproducibility, calibration uncertainty) and enables a quantitative assessment of the risk that a product will be incorrectly assessed as compliant or non-compliant. For this reason, it is part of guidelines such as VDA 5, ISO 14253 and GUM.
Since expanded measurement uncertainty can serve as proof of capability for inspection processes, especially when capability indices are not applicable or meaningful enough, it also plays an important role in the ComPro VDA 5 training course.
How do you calculate measurement uncertainty in accordance with VDA 5?
Once the factors influencing the measuring system or measurement process have been identified, the standard uncertainty is first determined for each of these factors. To do this, either a series of measurements is analysed (Method A) or prior information is used (Method B).
The combined standard uncertainty is then calculated by squaring and summing the values of the standard uncertainties determined previously. Finally, the expanded measurement uncertainty is determined. To do this, the combined measurement uncertainty is multiplied by the expansion factor k.
The expanded measurement uncertainty, together with the original measured value, forms an interval within which the true value lies with the chosen probability.
Which statistics are used in VDA 5 and ISO 22514-7?
According to VDA 5 and ISO 22514-7, QMP is the capability ratio of the measurement process, defined as the percentage ratio of the double expanded measurement uncertainty to the tolerance. It forms the basis for evaluation, as it relates the measurement uncertainty to the tolerance. QMS, accordingly, refers to the measuring system.
According to ISO 22514-7, CMP is regarded as a capability index for the measurement process and describes the ratio of the tolerance width to the variation in the measurement process. CMS is used in the same way for the measuring system.
VDA 5 uses the capability index Cg to describe the capability of the measuring system. This parameter relates to the capability of the inspection equipment, i.e. whether the variation in the measuring system is small enough in relation to the tolerance.
The same applies to the critical capability index Cgk, which also takes into account the systematic deviation and thus the centre of the measuring system.
