(9)The realisation of a work corresponding to the requirements specified by a contracting authority requires that the authority in question must have taken measures to define the type of the work or, at the very least, have had a decisive influence on its design. Whether the contractor realises all or part of the work by his own means or ensures their realisation by other means should not change the classification of the contract as a works contract, as long as the contractor assumes a direct or indirect obligation that is legally enforceable to ensure that the works will be realised.