This question already has an answer here:
Old application that is used by 50-60.000 paying customers. Company is several hundred people big. Application has a lot of business critical code (30% of all code) written in classic asp. Application has a lot more .net code. Application has a COM+ bridge for enabling asp to "talk" to .net Organization lacks some/a lot knowledge on what is causing the 10-20% server-reset per day (might be due to COM+ ?) There is no red line through the application; no architecture, no real patterns etc. The application has been like this for at least 5 years. The asp code base is increasing, slowly but certainly.
I have read refactoring stories and I have knowledge on why you some of the times should not re-write a system.
I would love for the old asp code to vanish as well as the COM+ component. But the pain is that no one really knows what is going on inside the asp classic code and the attitude inside all the teams are "this is just how it is".
Down the line, this causes a lot of other issues like recruiting, dev effeciency, business needs that cannot be met, scale etc.
With these little facts, does that justify a re-write of the asp code and the removal of the COM+ component ?
How would you go about it ?