This article is devoted to an approach to develop a safety system process according to functional safety standards. With the development of technologies and increasing the specific energy stored in the equipment, the issue of safety during operation becomes more urgent. Adequacy of the decisions on safety measures made during the early stages of planning the facilities and processes contributes to avoiding technological incidents and corresponding losses. A risk-based approach to safety system design is proposed. The approach is based on a methodology for determining and assessing risks and then developing the necessary set of safety measures to ensure that the specified safety indicators are achieved. The classification of safety measures is given, and the model of risk reduction based on deterministic analysis of the process is considered. It is shown that the task of changing the composition of safety measures can be represented as the knapsack discrete optimization problem, and the solution is based on the Monte Carlo method. A numerical example is provided to illustrate the approach. The considered example contains a description of failure conditions, an analysis of the types and consequences of failures that could lead to accidents, and a list of safety measures. Solving the optimization problem used real reliability parameters and the cost of equipment. Based on the simulation results, the optimal composition of the safety measures providing cost minimization is given. This research is relevant to engineering departments, who specialize in planning and designing technological solutions.