In reference to broken windows, are there times when refactoring is best left for a future activity?For example, if a project to add some new features to an existing internal system is assigned to a team that has not worked with the system until now, and is given a short timeline in which to work with - can it be ever be justifiable to defer major refactorings to existing code for the sake of making the deadline in this scenario? 
When is it acceptable to NOT fix broken windows?
project management;refactoring;maintenance