1. A computer system for managing air cargo yield for optimising a yield parameter resulting from assigning an offered capacity offered by a future instance of a cargo flight to each one of a plurality of different categories of requests competing for the capacity, the computer system comprising: a memory; and a processor in communication with the memory, wherein the computer system is configured to perform a method, the method comprising: defining the offered capacity by a weight capacity variable and a volume capacity variable, the weight variable and the volume variable independent relative to each other; storing a set of historical profiles for each one of a plurality of previous instances of the cargo flight, the set including a historical profile of an historical value of the weight variable and the volume variable reserved by each category, assigning a probability to each previous instance of the cargo flight, estimating a potential profile of a potential value of the weight variable and the volume variable from each historical profile according to a corresponding current value of the capacity variable reserved by the category for the future instance of the cargo flight and according to a corresponding unconstrained demand of the weight variable and the volume variable for the category in the previous instance of the cargo flight, defining a historical scenario for each previous instance of the cargo flight, the historical scenario including a final potential capacity variable from each corresponding potential profile, the final potential variable comprising a final potential weight capacity variable and a final potential volume capacity variable; determining an authorisation to allocate the offered capacity for the weight variable and the volume variable of each category in the future instance of the cargo flight by applying a stochastic model to the historical scenarios according to the corresponding probabilities; and providing a determination to a display of a computing unit of an acceptance or a rejection of a request for the cargo flight based on the authorization.