The complexity of modern projects makes the proper management of them crucial. The volatile environment of the twenty-first century means that it is important to choose the right moment to start a project. Because the decision to start is irreversible, we are dealing with a real option. The paper presents a outline of Support System for choosing the right moment to start a project on the basis of multi-state real options. The system is based on knowledge of the future changes in the factors affecting the results of the project The TOPSIS method was used to choose the efficient decision.