Device for automatic chemical analysis

An automated chemical analyzer for automatically analyzing a plurality of samples in separate reaction vessels for at least two different analytes, comprising a plurality of assay resource stations through which each of said reaction vessels must pass, each assay resource station including an assay resource capable of performing a predetermined operation upon one or more of the reaction vessels within a first indexing time, the first indexing time defining a time cycle of fixed duration;

• and analyzer control means comprising scheduling means for allocating assay resources to one of the reaction vessels as a function of an integral multiple of said time cycle and transfer control means for controlling transfer of the reaction vessels directly from one assay resource station to another according to a chronology selected from a plurality of different predetermined chronologies, and where at least one chronology requires a reaction vessel to be acted on by at least two assay resource stations more than once.