1. A computer implemented method of executing a script comprising one or more operations, the method comprising: parsing each of a plurality of operations into an operation name and an associated input data set description to obtain one or more parsed operation descriptions; determining, using a selected parsed operation description corresponding to a selected operation, that the selected operation has previously been executed on an associated previous execution input data set; linking an output of the selected operation to a stored output of the selected operation previously executed on an associated previous execution input data set to produce a revised script; and executing the revised script.