How to decide fate of our relationships

For past some days, i have been thinking that how we get upset with the people we used to like and getting upset to the extent that we like to end our relationship with them. Starting any relationship is not a very tedious job the comlexity comes while maintaining it. Sometimes the issue involved is so much grave that you can not do anything else other than ending the relationship. But most of the time, i believe that issues may look grave in their individuality but may not be so much painful to warrant the ending of relationship if seen in totality. Very often, when our loved one does a thing which displeases us to a great extent an ill feel pervades into our mind. We start avoiding the person and then if no settlement is done fastly, the relationship ends very soon. A good relation thus die down too untimely and too unreasonably. When we set out on such agenda, we must give a thought to the times we enjoyed each other company, the times when that person helped us or took care of us. We must think about the good qualities he is having. And then we should arrive on a judgement that whether this guy/gal is basically of the type with which i can never keep a friendship or not. In most of the cases, i hope that answer would come as " Howsoever bad this single episode be, i know that this guy is great otherwise and i can forgive him this small folly on his part."
Who doesn't do a mistake ? Even our birth relations like our Parents, brothers or sisters many times treat us unfairly but it never sounds the death knell to our relationship with them because most of the time we don't have such choice at that time in spite of our momentary willingness to do so. And later you would always be thankful that you did not have that choice.
We must extend this unavailability of choice, atleast for some time, to our other relations as well.