This Masterthesis provides two contribution which have been tested into an industrial context, both aimed at improving efficiency of Scan Insertion phase. The first enhance the flow with the introduction of automation and of an abstract communication protocol. Results showed that after this improvement the flow was faster and less complex. The second is a procedure which can be used to select FFs to create a portion of the available scan chains to test only specific modules inside the design, trying to not loose fault coverage. Also in this case positive results were reached, with the possibility of reducing side effects by choosing among some tradeoffs.