Governments have a long history of working with the private sector under the traditional model for government service delivery. The City's traditional "delivery model" for capital projects is to treat the design, tender, construction, and operation and maintenance stages of a project as separate components. In each component, The City may or may not involve the services of the private sector (e.g. consulting engineers, architects, construction contractors, etc.).
In contrast, P3 delivery entails combining two or more of the project stages into a single bundle, and utilizing a single private sector bidder to deliver the bundle. In addition, the private sector may finance some or all of the capital required, rather than The City issuing debt or using other financing sources. P3s also tend to be long term arrangements, and may include incorporating not just the initial construction of a facility, but its ongoing maintenance and/or operations and/or service to the public, depending on the nature of the project. The City has increasingly bundled the design and construction (i.e. Design-Build discussed below) for infrastructure delivery, but has limited experience with the other aspects of P3s. While the focus is often on using P3s for the capital infrastructure, an important component of certain P3s can also be the delivery of programs and services.