Hi, Whatever makes the code not spending 5s at initialisation sounds a good idea. I have add a bunch of print statement inside you code and found the responsible line for the slow down of the init: precompiler.Run('TestSampleAnalyzer',[self.archi_info.ma5dir+'/tools/SampleAnalyzer/Test/Process/dummy_list.txt'],self.archi_info.ma5dir+'/tools/SampleAnalyzer/Bin/',silent=True): That line takes a full 5s. So I have just commented it and now this makes the code fast enough (0.4s). I have no idea what that lines does, but that's the bottleneck. Cheers, Olivier > On 23 May 2017, at 15:19, Benjamin Fuks