In recent years, the chemical and pharmaceutical industries have observed a noticeable decline in economic activity. This has resulted in many companies focusing on innovative research and development as they consider this key to business success. In particular, a number of leading industrial organisations have adopted the principles of Whole Process Design (WPD). WPD considers the optimisation of the entire product development process, from raw materials to end product, rather than focusing on each individual unit operation. The complexity involved with the implementation of WPD requires rationalised decision-making, often with limited or uncertain information. This paper presents the outcomes of two questionnaires that examined the requirements of professionals working within the chemistry-using industries with respect to developing a decision-making support tool. From the findings a methodology is proposed, the outcome of which allows a decision-maker to visually interpret their decision results with associated levels of uncertainty. A chemical route selection case study demonstrates and validates the application of the proposed methodology.