For many, happiness is defined by the measure of their success. However, I think this kind of ideology is small-minded and temporary. Happiness is an emotion that can come and go, but joy is a result of something greater than fleeting emotion and circumstances. In order to ensure happiness in all areas of life (career, family, etc.), I think it's important to identify where true joy can be found. For me, my joy is rooted in Jesus Christ.
Christ has been the one consistent factor in my life. He is the same yesterday, tomorrow, and today. Whenever I fail or mess up (which happens often), Christi is still there to offer grace.
My relationship with Christ and the joy that comes from it allows me the freedom to experience happiness in other areas of my life. Walking with Christ has stretched me in so many ways, and I've experienced a tremendous amount of personal growth as a result.
In addition to this, I believe it's important to understand yourself and establish a life goal/purpose. Personally, my purpose in life is to know, love, and glorify God. So, I want my career and relationships with others to be a reflection of this. If my career isn't pointing me to God or glorifying to Him, then I know I won't be happy.
I think to ensure happiness in all areas of your life, you must first identify where your joy is rooted--whether that be in specific relationships with family or friends or spiritually or somewhere else. Once you recognize where your joy comes from, then you can identify your life goal or "mission statement." Having identified your mission statement, this then acts as a benchmark to measure your life by. If you're not fulfilling your mission statement or life goal, perhaps it's time to move on and find something else.