Once we have gathered all the requirements, we need to develop them. First of all we need to normalize all the data from di”erent sources. We also need to structure these requirement data so that all data are in one form and can be taken on one document or database. We also need to ˆnd dependency between these requirements. For all of these activities, we need tools. If not advanced tools, then basic tools like word processors, Excel sheets, etc., can be used.