Process for evaluating the coke and/or bitumen yield and quality of a plurality of refinery feedstocks, by (i) providing a plurality of refinery feedstocks, (ii) placing a sample of each of the plurality of refinery feedstocks on a heating device, (iii) heating each sample under vacuum to a temperature in the range 300° C. to 420° C. using the respective heating device while measuring the weight loss of the sample, and then (iv) (a) measuring the bitumen quality of the vacuum residues formed, and/or (b)(i) heating the vacuum residues to a temperature in the range 450° C. to 600° C. using the heating device, while measuring the weight loss of the sample, and then (ii) measuring the coke quality of the products formed.