Assurance of learning continues to be a hot topic in higher education. Both accreditation agencies and employers are asking a key question: Are we graduating students who actually have the knowledge and skills that we promise? This case study focuses on business writing in an MBA program and presents a prescriptive, five-step program to improve MBA students' writing skills. The study provides example documents used in the assessment process and an example of data analysis used to "close the loop" in the assurance of learning cycle. The study concludes with lessons learned and recommendations for future improvements in the process. (Contains 3 figures and 2 tables.)