Is "management science" a subsection of economics? Reading about the academic journal Management Science, one can read the following:


  Management Science is a scholarly journal that publishes scientific research on the practice of management. (...) Our articles are primarily based on the foundational disciplines of economics, mathematics, psychology, sociology, and statistics, and we encourage cross-functional, multidisciplinary research that reflects the diversity of the management science professions.


So is management science (the scientific research that is published in journals like this) a separate science, similar to the way economics uses Mathematics? What is the view of economists on this?
The journal Management Science is a decent one. Many economists do publish on that journal. In fact, a quick look at its editorial board reveals many notable names, with the recent Nobel laureate in Economics Richard Thaler among the associate editors.

The field of management science is more interdisciplinary in nature. See Wikipedia's entry for it. To me, it's like operations research for business or applied microeconomics in the context of business decision-making. To call it a "separate science" is a bit too much, though.