Testing capability in mechanical engineering

When a component fails during operation, the first question is often:

Was the calculation carried out correctly and can anyone understand it?

This is precisely where the importance of testability becomes apparent:
It ensures that design decisions and calculations can be objectively verified - regardless of who originally carried them out.

In mechanical engineering, testability is therefore a central component of technical quality assurance.
It means that calculation documents are structured in such a complete, comprehensible and standard-compliant way that they can be technically assessed and validated by third parties, such as test centers, experts or customers.

Verifiability is not an additional work step, but the result of a clean, structured way of working.
A verifiable calculation includes:

• Complete recording of the input data (loads, geometries, materials, boundary conditions)

• Transparent presentation of the calculation approaches

• Clear references to standards and guidelines, e.g. DIN EN, VDI 2230 or FKM guideline

• Comprehensible result evaluation with safety coefficients and justifications

Only if these basic principles are fulfilled can a technical verification actually be checked.
This applies equally to strength verifications, bolted connections, pressure vessels or shaft calculations.

In practice, the topic of testability is encountered in many places:
in internal reviews, customer approvals, CE assessments or audits in accordance with ISO 9001.
Inspectors and auditors expect calculation verifications to be clearly traceable - with clear references to standards, boundary conditions and results.

If intermediate values, units or formula references are missing, a calculation quickly becomes an estimate.
This costs time, leads to queries and weakens the verification process.
Verifiable documentation avoids such uncertainties, creates trust and reduces coordination effort.

Testability and technical documentation are inextricably linked.
A calculation can only be tested if it has been fully documented.
The documentation forms the technical memory of the project. It records how and why a solution was created.

Complete documentation is therefore not only mandatory, but the basis of any professional verification.

Matching technical article: Technical documentation - the basis for safe and traceable designs

In Germany and Europe, the requirements for verifications and testability are clearly defined.
Regulations such as VDI 2230 for bolted connections, the FKM guideline for fatigue strength or the AD-2000 data sheets for pressure equipment specify how calculations and verifications are to be carried out and documented.
Anyone who applies these regulations and documents the results in a structured manner automatically fulfills the essential requirements for testability.

This conformity to standards is also a central component of every conformity assessment in accordance with the Machinery Directive 2006/42/EC and is regularly checked by testing organizations such as TÜV, DEKRA or DNV.

While testing capability used to depend primarily on experience and discipline, today it can be systematically ensured using digital tools.
Modern calculation systems support engineers in automatically documenting verifications, consistently recording boundary conditions and complying with the requirements of relevant standards.

In digital calculation environments such as MDESIGN, inputs, boundary conditions and results are documented automatically. In this way, a verifiable verification report is created directly from each calculation: traceable, standard-compliant and audit-proof in PDF/A-1a format.