If you find yourself consistently angry about another person’s failure to meet your expectations it may be a good idea to focus on the overall goal you are trying to achieve.
For example, if your goal is to meet a friend for dinner and leave enough time to catch a movie, but your friend is often late (making it hard to catch the movie in time). You could just ask him or her to meet you earlier. Leaving yourself, and them, enough time achieve your ultimate goal will leave you relaxed instead of tense. Paying attention to the big picture can help you plan ahead and avoid being angry when things don’t work out.