dependability according to dictionary.com is:
capable of being depended on; worthy of trust; reliable; a dependable employee.
dependability is something you need to be when having a job for example; when having a job your manager has to be able to depend on you to do your job, show up on time. For me, my manager depends on his employees a lot to do the job when he isn't there sometimes your their alone and you have to do all the work on your own and really work hard. At night when its you and one other person you have to make sure everything is clean, sanitized, put away and ready for the night day. Being dependable is very important especially when your getting or having a job.
