Decision making can exist without problem solving. But problem solving always involves decision making.

Decision making is the ability to identify and choose alternatives by using logical and sound judgment based on available information. The decision-making process implies that many choices can become evident after an information gathering function (found in problem solving process) has occurred thereby reducing the amount of uncertainty and doubt regarding alternatives to allow a reasonable choice. Making group decisions may be referred to as consensus decision making.

Problem solving is a process that follows a logical sequence in examining issues and improving the quality of decisions to make effective interventions. This process, which can be completed independently or within a group (which may be referred to as joint problem solving), also helps to identify tools and techniques to apply to current and future situations.

Reach In, Reach Out, Reach Over: Conflict Management Pilot Program In North Carolina, North Carolina Department of Juvenile Justice and Delinquency Prevention – Center for the Prevention of School Violence Raleigh, North Carolina (2002)