State law specifies three general types of procurement approaches that state departments can use—design–bid–build, design–build, and public-private partnerships. The main difference between these approaches is which project phases—such as design, construction, maintenance, and funding—are performed under a single contract and which ones are performed separately. For example, under the design-bid-build approach, the state typically contracts with one firm to design an infrastructure project and a separate firm to build it. In contrast, under the design-build approach, the state typically contracts with one firm to design and build the infrastructure project.
For more information on public-private partnerships, see Maximizing State Benefits From Public-Private Partnerships. (PDF)