Optimised contractor involvement
Optimised contractor involvement (OCI) is a variation of the ‘early contractor involvement’ (ECI) model that has been adopted widely in the infrastructure sector on large and complex projects.
Devised by Steve Rowsell, Procurement Director for Crossrail, OCI is intended to ensure contract packages are subject to effective competition and maximum output with the available resources.
The subtle difference between ECI and OCI is that in ECI, a contractor’s skills are introduced early into a project to bring design buildability and cost efficiencies to the pre-construction phase. In OCI, contractors are brought in at a stage that is late enough for the target price to be quite firm, but early enough for them to be able to influence buildability and value engineering.
ECI has been used on by many public sector construction clients, however, some clients have been reluctant to adopt the strategy because of concerns associated with appointing contractors before permissions such as planning have been granted, and issues to do with attracting accurate and competitive prices from contractors when the design is not yet well advanced.
The OCI approach optimises contractor involvement, rather than simply trying to make it as early as possible, waiting till a point when the contractor is more likely to be able to offer an accurate and competitive price.
The contractor input into the design under OCI generally takes place post contract award, whereas in ECI, it takes place pre-contract award, under an arrangement such as a Pre-Construction Services Agreement.
The OCI approach may adopt a two stage selection process. The first stage is based on an assessment of the contractor’s technical and quality competence. The second stage involves the shortlisted tenderers carrying out a review of the client’s design. The tenderers then submit their final proposals, including a target price.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
The heritage of nuclear and conventional power stations.
New measures to stop people being ripped off
Government to protect families from cowboy builders and aggressive bailiffs.
New Futurebuild showcase brings an innovation-first approach.
National Planning Policy Framework
Understanding the 2026 changes.
ECA's public affairs priorities
Member consultation opens to shape priorities for 2027 to 2030.
Dutyholder responsibilities from 1 July 2026.
Where performance meets practice
The Building Envelope Stage at UKCW Birmingham.
CIAT publishes briefing on planning reforms.
Leaders in Learning for Practice Network
Call for conservation leaders in learning to register interest in new network.
The importance of early engagement
Construction lessons from the Trillium HealthWorks Experience Centre.
Mayors are to be given planning call in powers
Mayors across England will be able to make the most important planning decisions.
The Master Builder: William Butterfield and his times. Book review.

















