Why should decision makers focus only on the relevant costs for decision making?

Decision makers should focus only on relevant costs because these are the costs that will directly impact the decision at hand, ensuring that resources are allocated efficiently. By concentrating on costs that will change as a result of the decision, they can avoid being influenced by sunk costs or other irrelevant expenses that do not affect future outcomes. This approach helps in making more informed, effective choices that align with strategic goals. Ultimately, it leads to better financial performance and optimized resource utilization.