Ward Cunningham introduced the technical debt metaphor as a method to highlight the potential for higher costs in product development from postponing some work on software in order to release other parts faster. The comparison between financial debt and the term technical debt was meant to demonstrate the eventual need to complete postponed work and repay the principal of delaying it. Technical debt also alludes to the possibility that interest costs, associated to postponed work, can become so high that they impede any other important work from being done on a project. For these reasons, technical debt is a useful concept – as it clearly communicates the danger of postponing work. However, metaphors often conflate two comparable situations, to two identical treatments of similar situations. This can be avoided in the financial debt/technical debt coupling, by using the financial metaphor to identify the economic forces behind technical debt.