The engagement of Denise Allison and Tracy Ferguson is announced today. Ms. Allison is the daughter of the late Brenda and Wayne Allison of Chattanooga. The prospective bridegroom is the son of the late Stylist Ferguson of Danville, Va. The wedding is planned for Saturday, May 16, at The Wedding Chapel. Ms. Allison graduated from City High School. She is a project development and reports analyst with BlueCross BlueShield of Tennessee. Mr. Ferguson is employed as a carpenter.