for a specified period of time on behalf of the owner. A minima, public-private partnership refers to the idea of cooperation between the public sector and the Private sector. The following models are usually used for P3 projects, though they are also sometimes used for private sector projects. Build-Finance (BF) The private actor builds the asset and finances the cost during the construction period, afterwards the responsibility is handed over to the public entity. In terms of private-sector risk and involvement, this model is again on the lower end of the spectrum for both measures. Build-Operate-Transfer (BOT) Build-Operate-Transfer represents a complete integration of the project delivery: the same contract governs the design, construction, operations, maintenance, and financing of the project. After some concessionary period, the facility is transferred back to the owner. Build–own–operate–transfer (BOOT) A BOOT structure differs from BOT in that the private entity owns the works. During the concession period, the private company owns and operates the facility with the prime goal to recover the costs of investment and maintenance while trying to achieve a higher margin on the project. BOOT has been used in projects like highways, roads mass transit, railway transport and power generation. Build–own–operate (BOO) In a BOO project ownership of the project remains usually with the project company, such as a mobile phone network. Therefore, the private company gets the benefits of any residual value of the project. This framework is used when the physical life of the project coincides with the concession period. A BOO scheme involves large amounts of finance and long payback period. Some examples of BOO projects come from the water treatment plants. Build–lease–transfer (BLT) Under BLT, a private entity builds a complete project and leases it to the government. In this way the control over the project is transferred from the project owner to a lessee. In other words, the ownership remains by the shareholders but operation purposes are leased. After the expiry of the leasing the ownership of the asset and the operational responsibility is transferred to the government at a previously agreed price. Design-Build-Finance-Maintain (DBFM) "The private sector designs, builds and finances an asset and provides hard facility management or maintenance services under a long-term agreement." The owner (usually the public sector) operates the facility. This model is in the middle of the spectrum for private sector risk and involvement. Design–build–finance–maintain-operate (DBFMO) Design–build–finance–operate is a project delivery