It is very important to have an up to date inventory of all of the assets under the management of an agency. The inventory should beging at asset commissioning and be maintained thoughout the life of the asset and include documentation of any maintenance and rehabilitation treatments applied to maitain the asset in a serviceable condition as well as the documentation of any other changes in the asset, e.g. layers of pavement milled off prior to adding new asphalt overlays. The condition of the asset should be documented at appropriate intervals to assist in determining the remaining useful life of the asset as well as to develop performance models for planning and budgeting purposes. Each of these elements are discussed further in the following sections.