Meet the Instructor

Don Mansfield is a recognized expert in the contracting career field. He has over 26 years of experience as a federal acquisition professional. During this time, he has served in the following capacities:

• 2019 to present: Owner, Don Acquisition LLC
• 2006 – 2019: Professor of Contract Management for the Defense Acquisition University (DAU)
• 2003 – 2006: Head of Procurement and Proposal Evaluation and Deputy for Small Business at the Southwest Regional Maintenance Center (SWRMC)
• 1999 – 2003: Contracting/Grants Officer at the Space and Naval Warfare Systems Center (SSC)
• 1998 – 1999: Contract/Grants Administrator at the Office of Naval Research (ONR)
• 1995 – 1998: Contract Specialist at the Navy’s Fleet and Industrial Supply Center

In 2019, Mr. Mansfield received the President’s Award for exceptionally meritorious achievement during his 13 years as a Professor of Contract Management at DAU. He taught various courses in DAU’s contracting and small business curriculum, training over 3,000 students in Federal contracting. He led the development of Federal Acquisition Regulation Fundamentals (CON 090), for which he won both individual and team corporate awards in 2010. He also managed the course for 4 years and taught it 45 times. It became the highest-rated instructor-led course in DAU in terms of general benefit and direct applicability to on-the-job tasks.

Meet the Instructor

Ed Chevalier recently joined Don Acquisition LLC as an instructor following his retirement from Civil Service in September 2024, where he served as a Professor of Contract Management for the Defense Acquisition University (DAU).

From August 2022 to September 2024, Ed held the role of Senior Client Liaison Officer and Certified Instructor at DAU. In this capacity, he led portfolio-wide engagement efforts with NAVFAC regions, designing mission-specific learning solutions and closing critical training gaps. His contributions earned him the distinction of Client Liaison Officer of the Year for DAU West in 2023. During his tenure, Ed:

• Developed and delivered NAVFAC-specific contract training in areas such as Technical Analysis, FAR 16.505 Fair Opportunity, RFI Response, Evaluation Factor Development, and FAR Part 15 Source Selection.
• Achieved an exceptional 6.86 Likert score average in 2024 across all courses taught, reflecting excellence in instructional expertise, communication, and student engagement.
• Was widely recognized across DAU for his deep expertise in construction, Architecture/Engineering, and services contracting—particularly for NAVFAC and its policy nuances.

Meet the Instructor

Hallie Tremaine Balkin brings over 20 years of experience in federal acquisition, agile contracting, and U.S. defense. She currently serves as General Counsel at Rhombus, where she leads all legal, compliance, and government contracting functions for the company. At Rhombus, Hallie drives strategy at the intersection of law, innovation, and mission delivery—helping accelerate secure, compliant growth in the federal and defense markets.

In addition, Hallie is an Adjunct Professor at The George Washington University Law School, where she developed and teaches the school’s inaugural course on Other Transaction Authority (OTA).

Previously, she was Lead Counsel for Microsoft’s Department of Defense and Defense Industrial Base business, supporting a team that achieved $6.5B in 2024 revenue. Before that, she served as Director for OTA at the Defense Acquisition University (DAU), where she developed the OTA credential. Hallie also provided legal guidance on high-impact efforts such as Operation Warp Speed and the DoD OTA Guidebook.

Earlier in her career, Hallie served as Associate Counsel at Naval Information Warfare Systems Command (NAVWAR), leading acquisition efforts for major projects such as the $2B NOBLE contract and the Navy’s first AI Prize Challenge (AI ATAC).

Hallie earned her Juris Doctor from Thomas Jefferson School of Law and her B.A. in Political Science from San Diego State University.

Meet the Instructor

For over three decades, Jon Wester served the U.S. Department of the Navy, retiring as Contracts Branch Head at the Naval Information Warfare Systems Command in San Diego, California. From 2014 to 2025, he managed a team handling over $500 million in annual contract awards for defense systems and engineering services, overseeing all contract stages from planning to close-out. Prior to this, he worked over 20 years as a contracting officer and contract specialist across several Navy commands, including overseas roles in Yokosuka, Japan, and Naples, Italy, supporting logistics contracting for Navy facilities and deployed assets.

Mr. Wester also taught Cost and Price Analysis at the Defense Acquisition University and led annual contracting training for Navy financial specialists. He implemented a Commercial Solutions Opening (CSO) process for a Navy intelligence hub data system and served as lead contract negotiator for Taiwan’s $1 billion Po Sheng acquisition. With an MBA from Florida Institute of Technology and a BA in Linguistics (summa cum laude) from the University of California - San Diego, he received the 2006 Navy Acquisition and Competition Excellence Award and a Navy Meritorious Civilian Service Award in 2022.