A methodology for the ex ante evaluation of different processing options is proposed. Current processes for glucose oxidation and possible improvements using microreactor technology are investigated. As twofold prime research objectives, the oxidation with noble metal catalyst versus enzymatic oxidation and the oxidation under conventional process conditions versus under Novel Process Windows are explored. Operation and design of an active and stable catalyst, reactor performance, and work-up are included. This ex ante analysis gives information of the critical aspects of a process prior to technology development and facilitates the development of new process routes; especially valuable if step and paradigm changing routes are undertaken, with even no vague idea on their performance potential and with high technological risk. The methodology used for gluconic acid production will be transferred to other chemicals which have the potential in using microreactor technology and Novel Process.