David Hay, President of Essential Strategies, Inc. has extensive experience in the design and implementation of manufacturing planning and control systems. For five years he worked in the domestic and international divisions of a major pharmaceutical company, where he introduced the company to materials requirements planning, master scheduling, and related techniques. He has written detailed specifications for MRP processing, both as it applies to manufacturing and distribution. He has participated in the implementation of manufacturing planning and control systems worldwide.

For another five years, he worked for a company that produced chemical products and processed natural resources. As manager of manufacturing systems he was responsible for implementing manufacturing planning and control systems in seven quite different plants in five divisions. He used data modeling to maintain a consistent architecture across the plants, complying with the industry-wide principles as they were evolving, while still responding specifically to the particular needs of each plant.

In both positions, he developed and conducted extensive world-wide training programs in manufacturing practices and techniques.