In the design of a chemical process (CP), certain design specifications (for example those related to process economics, process performance, safety, and the environment) must be satisfied. During the operation of the plant. since design models have uncertainties associated with them, we need to ensure the flexibility of the CP. This means that within the region of uncertainty, all design specifications must be satisfied. In recent years, research has focused on the development of methods for flexibility analysis of the CP. There are three main sub-problems associated with flexibility analysis, namely evaluation of CP flexibility, evaluation of CP structural flexibility and determination of the optimal regime over which the flexibility of the CP is guaranteed. We have developed a general approach to solving the sub-problems based on the split and bound strategy.