A cash-flow diagram is a tool used by accountants and engineers, to represent the transactions of cash which will take place over the course of a given project. Transactions can include initial investments, maintenance costs, projected earnings or savings resulting from the project, as well as salvage and resale value of equipment at the end of the project. Cash flow diagrams may also be used to represent payment schedules for bonds, mortgages and other types of loans.It is often used with a break even sheet and a balance sheet in order to see where money is being made or lost. Also it is used to monitor results of different things. For instance when changing variables it will see if they are successful or not in causing future profit.