The objective of the conceptual design is to reflect the requirements of the Owner Project Requirements (OPR) in a first design that allows us to have a first assessment, even approximate of the economic cost of the project.
For the realization of this design it is possible that we may have existing documentation or may have to take data (through an audit or a preassessment) and elaborate them.
This is an iterative model: if we change the conceptual design, we must verify whether we are changing the OPR as well and submit it again for approval.
We do not recommend bidding for purchase based on a conceptual design, as we may find surprises in the execution with additional costs and unforeseen events that may compromise the achievement of the objectives sought in the OPR. The lack of definition can only go against the success of the project.