To evaluate if a goal is worth,we should consider about several problems.at first,the target will take how much benefit to us,the more benifit bring ,the goal is more worth to achieve.futhermore,if the return from the goal is smaller than the expend,this goal is not worth to gain it...
When investigating maintainability and attainability, one has to start by precisely defining what should be maintained or attained and how this can be accomplished. Note, however, that the concepts of maintainability and attainability can be used for every discrete-time Markov process that allows ...