Abstract: A system is described that has a first engine configured to determine an assignment of a resource to a task. The assignment is based on a schedule representation comprising at least resource profile data and task profile data. The resource profile data represents a resource profile associated with the resource and the task profile data represents a task profile associated with the task. The system also has a data store configured to store a set of rules, the set of rules comprising data indicative of one or more functions to be applied to one or more input data sources to output at least one variable value for the schedule representation. This then allows a second engine coupled to the data store to be configured to update the schedule representation in accordance with the set of rules.