Rehabilitation: 

The International Infrastructure Management Manual defines asset rehabilitation as: “Works to rebuild or replace parts or components of an asset, to restore it to a required functional condition and extend its life, which might incorporate some modification.” 

Restoration: 

The American Water Works Association Definitions Guidebook defines restoration as “Maintaining a majority of the existing Asset, while transforming its appearance and functionality to ‘as new,’ and in some instances, ‘better than as new.’” 

Rehabilitation or restoration might be more expensive than a repair, but it should increase the life expectancy of the asset beyond what a repair would provide. Rehabilitation should be less costly than a replacement and usually provides less useful life than a full replacement.  

In some cases, rehabilitating an asset can bring it close to new. For example, when relining a pipe, the expected useful life of the relined pipe might be almost as much as a new pipe. Because pipe lining can be completed without creating a large trench, it can be considerably less expensive than pipe replacement. Sometimes rehabilitation can be completed more than once, while other times, it can only be completed once. 

Rehabilitation efforts should focus on the long-term impact on operations and maintenance. Asset rehabilitation should only be performed after considering the full spectrum of asset operability, risk management, and cost.