PPPs come in all shapes and sizes. Financing is an interesting distinction between PPP models. It also affects the types and levels of private involvement. One model more inclusive of everything from designing to operating/maintaining may be more suitable for hard economic infrastructure that can sustain "itself", (such as toll-roads or airports) while a second model requiring public infusions over time through operations support or availability payments may be more appropriate for soft infrastructure.
Listed below are NCPPP's types[xxiii] of public-private partnerships:
• O&M: Operations and Maintenance
• OMM: Operations, Maintenance & Management
• DB: Design-Build
• DBM: Design-Build-Maintain
• DBO: Design-Build-Operate
• DBOM: Design-Build-Operate-Maintain
• DBFOM: Design-Build-Finance-Operate-Maintain
• DBFOMT: Design-Build-Finance-Operate-Maintain-Transfer
• BOT: Build-Operate-Transfer and BTO: Build-Transfer-Operate
• BOO: Build-Own-Operate
• BBO: Buy-Build-Operate
• Developer Finance
• EUL: Enhanced Use Leasing or UA Underutilized Asset
• LDO or BDO: Lease-Develop-Operate or Build-Develop-Operate
• Lease/Purchase
• Sale/Leaseback
• Tax-Exempt Lease
• Turnkey
There are a lot of similarities between types of PPPs, but they differ regionally and nationally.
Perhaps of most interest in the A/E/C community are the various design-build public-private partnerships. Out of the list above, approximately 36% involve "design", 57% involve "build/construct", and 36% include "maintain." The NCPPP lists the following as benefits of design-build (DB) PPP projects:
1. Reduce time
2. Save money
3. Provide stronger guarantees
4. Provide a single point of responsibility
5. Ownership retained by public entity
The key element of defining a PPP once again comes down to the "partnership", component. If not for that, there would be little to differentiate a traditional DB project from a DB PPP.