(91)To ensure that in any event the AIFM performs investment management functions, the AIFM should not delegate its functions to the extent that, in essence, it can no longer be considered to be the manager of the AIF and to the extent that it becomes a letter-box entity. The AIFM should at all times keep sufficient resources to supervise the delegated functions efficiently. The AIFM has to perform itself investment management functions, to have the necessary expertise and resources, to keep the power to take decisions which fall under senior management responsibility and to perform senior management functions, which could include implementation of the general investment policy and investment strategies.