The Bank for International Settlements has argued that macroeconomic stress tests which assess the financial system as a whole are ill-suited as early warning devices. That is, they are not able to detect vulnerabilities during seemingly stable times. Instead, they are useful as crisis management and resolution tools, and can discipline thinking about financial stability risks. The report stresses that such tools should be seen as a complement, and never a substitute for other processes, and warns of unreasonably high expectations for what such tests can do, despite the benefits they bring.