When should the warranty period for a machine commence?

The most appropriate time for the warranty period for a machine to commence is after successful acceptance testing. This is because acceptance testing is a critical phase where the machine is evaluated to ensure it meets the required specifications and performance standards agreed upon in the contract. It provides a formal confirmation that the equipment is functioning properly and satisfies quality criteria before it is officially accepted for use.

Starting the warranty after acceptance testing allows the manufacturer or vendor to address any potential issues arising during this testing phase before the warranty period begins. If the warranty were to start upon delivery or after initial maintenance, there could be disputes regarding whether the issues arise from manufacturing defects or from improper installation or maintenance. Thus, aligning the warranty period with successful acceptance creates clarity and mutual agreement on the machine's operational capability at the outset of its usage.