Assembly models enable automatic creation of a full bottom-up cost estimate making them powerful tools for optioneering and target setting for a range of performance metrics. We have extensive experience in the creation of bespoke assembly models that can provide full bill of quantities cost, programme, carbon and operational expenditure estimates from limited early-stage design information through to embedded model design and parameter assumptions.
The tool is designed to allow basic parameters for principal assets to be defined, from which a full bottom-up estimate is automatically produced, utilising a central cost library. As the design matures, further asset details can be added that override default assumptions. This enables the impact of cost and design changes to be immediately seen across the entire programme, and the effects of different procurement strategies to be explored with little effort.
Our experience of developing assembly models extends across the infrastructure sector with commissions for HS2 Phase 1 and Gatwick Airport. In the UK water sector, we have worked closely with the Environment Agency to trial assembly models producing two exemplar outputs, prototyped in an auditable Excel-based platform which is then transferred into the CostOS estimating system.