This paper describes the design and subsequent development of a microcomputer-based Decision Support System (DSS) that utilizes heuristic simulation techniques to plan logistics and distribution activities at a strategic level, and to measure their impact on overall corporate profits. The system provides a deterministic tool to simulate multi-echelon networks composed of multiple product categories and transportation modes, involving both single and mixed product orders. These conditions may be analyzed under varying customer service levels. The system has been tested and validated by experts from industry.