Decision making is important in business. Unfortunately, people are not always naturally inclined to make the best decisions. Fortunately, management science serves the role of helping people to make more informed and logical decisions.
One of the roles of management science in decision making is to subdue human emotion. Human emotion can get in the way of decision making. For example, a person might be emotionally attached to a project that logically will not be profitable; management science tools can be used to identify the rational decision, which is to abandon the project.
Often, a decision will involve a complex web of causes and effects. The human brain simply cannot handle so much data. Management science offers methods for arranging this data in a way that it can be interpreted easily.
Humans are naturally inclined to have biases. Often, people aren't even aware of these biases. Biases can be very simple, such as a subjective preference for the color yellow rather than the color blue. Management science removes human biases from the decision making process.