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Meet Our Staff

Senior Director


Charles Barbara

Assistant Director


Jeffrey Appelbaum

Jeff has over 25 years of experience in Information Systems and Operations. Prior to joining The Johns Hopkins Health System, Jeff served as Chief Information Officer, Information Systems Director, and Operations Director.

Senior Project Administrator

Shereen Jahed

Shereen Jahed

Shereen Jahed is a Senior Project Administrator in the Operations Integration Department. Shereen has held multiple leadership positions throughout the institution since 2004. She is solutions-focused with extensive experience spanning financial management, marketing coordination, project and event management.

Shereen is a focused relationship builder and strategist with strong communications abilities and skill in cultivating cross-functional alliances. A proven catalyst in driving service improvements, Shereen consistently enhances customer satisfaction and drives revenue generation.

A University of Maryland alumna, Shereen earned both her Master of Science in Healthcare Administration and Bachelor of Arts in Communications degrees.

Project Administrators

Scott Levin

Scott Levin, Ph.D.

Dr. Scott Levin is an Associate Professor in the Department of Emergency Medicine and holds a joint appointment in the Department of Applied Mathematics and Statistics. He also works as a member of the Department of Operations Integration to forward operational, quality, and financial improvement initiatives within the Johns Hopkins Health System.

Prior to joining The Johns Hopkins Health System, Dr. Levin completed his PhD in biomedical engineering at Vanderbilt University. His work focuses on the use and development of systems engineering tools to study and improve the effectiveness, safety and efficiency of health care delivery.  Dr. Levin's current research is directed toward determining how scarce health care resources may be managed and deployed to best care for patient populations.  This includes an emphasis on systems engineering techniques aimed at improving quality of care, access to care, and medical decision making.

Dr. Levin is actively involved in research efforts for the National Science Foundation (NSF), National Institutes of Health (NIH), and Department of Homeland Security National Study Center for Preparedness and Catastrophic Event Response (PACER).  He has authored and reviewed numerous publications which apply systems engineering methods to medicine.

Diego Martinez

Diego Martinez, Ph.D.

Data scientist Diego Martinez develops and applies advanced data analysis and modeling techniques to data from electronic medical records, health status monitors, real-time location systems, among other information technology systems in the hospital. His work is focused on creating, deploying, and determining the effect of data tools on improving healthcare delivery. He is also an Assistant Professor in the Department of Emergency Medicine.

Prior to joining The Johns Hopkins Health System, Dr. Martinez earned his Ph.D. in industrial engineering from the University of South Florida under the supervision of Dr. Jose Zayas-Castro (working in conjunction with the Tampa General Hospital and BayCare Health System), followed by subsequent postdoctoral training at the Johns Hopkins University under the supervision of Dr. Scott Levin. Dr. Martinez's work has appeared in top medical and engineering journals including JAMA, BMC Medical Informatics and Decision Making, Applied Health Informatics, and Health Care Management Science.


Syedmehdi Rizvi, M.S., M.D.

Mehdi obtained his Medical Degree by successfully honoring his clinical rotations in Chicago. His Masters in Health Care Management from Johns Hopkins University. His Lean Sigma training came from the Johns Hopkins Armstrong Institute. Prior to joining Hopkins, Mehdi was a consultant for a Baltimore healthcare consulting firm, working with clients on startups to Federally Qualified Health Systems.

In his spare time he volunteers for an international medico-humanitarian organization known as "IMI" and serves as a board member for the Hopkins Biotech Network. Mehdi has done pro-bono work for the National Institute of Health, National Kidney Foundation, Cancer Support Group and Jewish Community Center. Mehdi is also the co-founder of the Private Equity & Venture Capital organization at Johns Hopkins' Carey Business School.

Administrative Coordinator


Mia Oliver

Mia Oliver is an Administrative Coordinator for the Department of Operations Integration since 2015. She is responsible for processing information into the SAP database, managing multiple appointment and calendar meetings, and executing routine clerical duties within the department. Prior to her role, Mia participated in The Johns Hopkins Summer Jobs Program while attending high school. With her exceptional performance and work ethic, she was then able to join the O.I. department. Mia is also a full-time student at Coppin State University where she is obtaining her Bachelor's Degree.

Administrative Resident

Anthony Tripp

Anthony Tripp

Anthony Tripp is an Administrative Resident for Operations Integration, assisting in the design and implementation of operational improvement projects. He is currently a dual-degree candidate at Johns Hopkins University and Maryland Institute College of Art, earning a Master of Business Administration and a Master of Arts in Design Leadership. In his free time, he is involved with Design For America's Baltimore Community Engagement Consulting Team.

Prior to joining the Johns Hopkins Health System, he founded and directed Camp Cadet Leadership Development with the Pennsylvania State Police – Troop D, a youth development program cultivating leadership potential through hands-on activities and facilitated discussion. Anthony has also done independent consulting projects with various organizations in the Greater Pittsburgh Area.