The concept is analogous to financial portfolio management, but there are significant differences. Financial portfolio assets typically have consistent measurement information (enabling accurate and objective comparisons), and this is at the base of the concept’s usefulness in application to IT. However, achieving such universality of measurement is going to take considerable effort in the IT industry (see, for example, Val IT). IT investments are not liquid, like stocks and bonds (although investment portfolios may also include illiquid assets), and are measured using both financial and non-financial yardsticks (for example, a balanced scorecard approach); a purely financial view is not sufficient. Finally, assets in an IT portfolio have a functional relationship to the organization, such as an inventory management system for logistics or a human resources system for tracking employees' time. This is analogous to a vertically integrated company which may own an oil field, a refinery, and retail gas stations.