This form of document contrasts with that of bills of quantities in which such tendering and estimation is limited to the materials in the completed work.
Operational bills have the advantages of enhancing communication between design and production, enabling realistic tender pricing, and making the preparation of critical-path analysis easy for the contractor.
[1][2][3][4] Operational bills were proposed and developed by Edward Skoyles at Building Research Establishment in the 1960s.
[1][2] Priced-activity schedules of the New Engineering Contract are a modern related form, prepared by the contractor.
In this, the operations are described in terms of the rules of the standard method of measurement rather than labour and materials.