This paper proposes a framework for fast short-term scheduling and steady-state voltage control in distribution systems enabled with both continuous control devices, e.g., inverter interfaced DGs and discrete control devices (dcds), e.g., on-load tap changers (oltcs). The voltage-dependent nature of loads is taken into account to further reduce the operating cost by managing the voltage levels. The branch and cut method is applied to handle the integrality constraints associated with the operation of dcds. A globally convergent trust-region algorithm (tra) is applied to solve the integer relaxed problems at each node during the branching process. The tra sub-problems are solved using the interior point method. To reduce the branching burden of the branch and cut algorithm, before applying tra at each node, a simplified optimization problem is first solved. Using the convergence status and value of the objective function of this problem, a faster decision is made on stopping the regarding branch. Solving the simplified problem obviates the application of tra at most nodes. It is shown that the method converges to the optimal solution with a considerable saving in computation time according to the numerical studies.