The present invention relates to a method of assigning objects to processing units of a cluster of processing units, each one of the objects having an object size and an object load, each one of the processing units having a storage capacity and a load capacity, the method comprising the steps of: a) calculating an index based on object size and object load for each one of the objects, b) sorting of the objects by index to provide a sequence of objects; c) for each processing unit of the cluster: assigning of one or more of the objects to the processing unit in sequential order until a remaining storage capacity and/or a remaining load capacity of the processing unit is too small for consecutive objects of the sequence; deleting of the objects that are assigned to the processing unit from the sequence.