Solving Conditional Models by Using a Boundary Crossing Algorithm

In this paper we investigate the solving of conditional models using the boundary crossing algorithm proposed by Zaher (1995). He proposed this algorithm as an alternative to using MINLP techniques for solving. This algorithm involves the execution of several well differentiated activities including logical analysis and continuous reconfiguration of the equations constituting the problem, calculation of Newton-like steps, and the calculation of subgradient steps. In this paper, we describe the practical implementation of the boundary crossing algorithm as a conditional modeling solution tool. In such an implementation, we have integrated the entities created and/or used to perform each of the activities in an object oriented solving engine: the conditional modeling solver CMSlv. Also, we describe and solve several examples of conditional models in chemical engineering. Finally we discuss the scope and limitations of the algorithm.