Speculate why the maintenance phase of SDLC is often so much

Speculate why the maintenance phase of SDLC is often so much larger than the other phases.  

Solution

One a software has completed all other phases of SDLC like testing coding etc the software is ready for production use in the industry. Since the technology keeps changing day by day which led to change in situations for which the software was developed. Now to cope up woth those changes the maintenance is required. If the maintenance or you can say small chnages are not done soon the software will not be good enough to use and will be rejected.