It's not only UML,flowchart,bubble chart that are important but also data dictionary, program specs as well as documentation within the code itself. This tools are useful even for the developer kay mahulog man ang system nga self explanatory na and this tools would come in handy especially kun daghan ang mag tabang ug code sa system. Have you tried working on a system that has been running for a couple of years with no existing documentation except for the code which only has a few comments, its such a PAIN especially kun newly hire pa gyud ka. Anyway ang naka ok ra nako sa una kay by the hour man ang bayad pero labad pud lagi sa ulo oy kay kinaraan kaayo ang style sa coding.