Basically what you are questioning is the nature of decision making. You are questioning whether it is an art or a science. The answer to this is that it is both. It is an amalgamation of the scientific body of knowledge as well as personalized application called art.
Three kinds of decision making
Decision making can be of three kinds. The first one tilts it to the scientific side, that is, the conditions are kept fixed and the decision is made. Secondly, it tilts to the art side where the conditions are uncertain and it requires the individual to apply his skills and expertise based on past knowledge and experience. And the third one is a mix of both, it is backed by certain conditions and yet has some variable components.
These are some pointers that need to be remembered to ascertain whether decision making is an art or a science:
It depends on present, past and future
Decision making is forward and backward looking. You need to consider your past performance and analyse it to study the methods and techniques used. This requires your personal rationale.
Until and unless you are well acquainted with how things work and use your past knowledge to judge the situation, appraising the conditions is not possible. Further, if you are talking about future, you might require some scientific techniques to get hold of the necessary data and take steps accordingly. It will also require some tools and techniques to ascertain goals and standards that you need to set.
Choices come into play
It has been stated very simply that decision making comes into the picture only because there are choices available. Now, if you are concerned with bringing forward new choices of your own, then decision making is termed as an art and if you are talking in terms of analyzing the choices you have, it can be called a science. It cannot be expressed in simpler terms.
Kind of question posed is also important
There were some people who put it in this manner, if the question revolves around personal matters, then you can call it an art because the choices will be more personalized and subjective. If the question pertains to work, you can call it a science because then that depends on some general guidelines and rules. Thus, the kind of question posed is also important and has a role to play in determining whether it is an art of a science.
Decision making is very crucial and an everyday affair for an entrepreneur and it is necessary for him to get well aware of this fact. He might, throughout his career, be in a condition to make use of his knowledge as well as scientific tool to come to a steady equilibrium. Thus, it can be called an amalgamation of both and not simply one as a whole.