For works contracts, the estimated value of the requirement is determined, irrespective of the number of economic operators called upon and the number of contracts to be awarded, by taking into account the total value of the works relating to an operation and the total estimated value of the supplies and services made available to the contractor by the purchaser where they are necessary for the performance of the works.
A works operation occurs when the purchaser takes the decision to implement, within a limited period of time and scope, a set of works characterised by its functional, technical or economic unity.