The required performance must be clearly stated by setting out details of operating outputs. The specification should not state how this performance is to be achieved. However, thought should be given to the practicalities of measuring performance - there is little point in relating payment to a performance standard where there is no way to measure it. Where, in exceptional cases, performance characteristics are insufficient to define the requirement, technical specifications may be used.
The project team must ensure that there are no inconsistencies between technical and performance characteristics. It is often useful to have a person independent of the project team to check these items for consistency and clarity.
Example
Design standards for cells in Police Stations have been developed within the public sector to meet the performance standards set out above in respect of prisoner safety. Bidders may, but are not required to, use these design standards. However, bidders should be aware that they would be fully responsible and accountable for meeting the performance standards. In choosing to use these design standards, the bidders must be satisfied that they are adequate to deliver the level of prisoner safety set out in this document. No risks in this respect will remain with the Police Service and no warranty as to the suitability of the standards is given.