Roy M. Neperud Jr., a senior systems analyst with RDW Systems Inc. in McLean, died Monday at his home in North Springfield. He had a brain tumor.

Mr. Neperud, who was born in Superior, Wis., served in the Army Signal Corps during World War II. He later graduated from the University of Wisconsin and later worked in Milwaukee and Chicago. In 1959, he joined the Systems Development Corporation and worked for them in Santa Monica, Calif., and Dayton, Ohio.

In 1966, he transferred to the Washington area with Systems Development. He remained with the firm until 1980, when he retired and joined RDW Systems.

Mr. Neperud is survived by his wife, Casey, of North Springfield; two sons, Peter, of Columbia, Md., and Matthew, of Free Union, Va.; one daughter, Catherine, of North Springfield; his father, Roy M. Neperud of Englewood,Fla.; three brothers, George, of Lake Ripley, Minn., Donald, of Amery, Wis., and Robert, of Waunakee, Wis.; three sisters, Joyce Rood of Indianapolis, Caroline Marquardt of Beaver Dam, Wis., and Mary Anderson of Eau Claire, Wis.; and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Hospice of Northern Virginia, 4715 N. 15th St., Arlington, Va., 22205, or to the Salvation Army.