It has been seen that it is a defense under Regulation 29 of the Electricity at Work Regulations for a duty holder to 'prove that he took all reasonable steps and exercised all due diligence to avoid the commission of that offence'.
It seems clear that the most effective method by which a duty holder can prove this in court would be by producing records. Records are essential if a proper and organised system of testing is to be established. The keeping of suitable records then is essential.
They provide evidence for the defense in the event of a prosecution; more practically, such records enable the close monitoring of the equipment highlighting potential faults or adverse trends. They are also essential in forming an accurate assessment of the necessary frequency of testing. For example, if over a number of consecutive test cycles few or no failures were recorded then he duty holder may consider reducing the frequency of tests, obviously the converse may also apply.