Perfect participles start with having -- the present participle form of the auxiliary verb for the Perfect -- and follow it with the past participle form of the verb -- made and said in this case -- which is also required for the Perfect construction. It's used to put a past reference into a participial clause, which is supposed to not be inflected for tense. Having said this, for instance, is a fixed phrase that means 'I have now said that which I needed to say. Now I change the subject.' It's perfect because it refers to to the relevant near past. – John Lawler Jul 30 '16 at 23:33