Research Question: This paper presents a simulation model aimed at improving total adequacy calculation for performance indicators of the first phase of production management. Motivation: Defining a set of adequate performance indicators that are specific and highly important for the observed planning phase has a significant impact on the effectiveness of the production process management. The result of the developed model is the value of selected performance indicators adequacy. Consequently, it can be concluded whether defined performance indicators are essential for the observed phase or other performance indicators should be selected. The monitoring of defined performance indicators should provide complete information about the observed phase and improvement of the planning phase management. Idea: The main idea of this paper is to develop a user-friendly simulation model, in accordance with the basic principles of spreadsheet engineering, for improving the selection of adequate performance indicators. This model is intended for use in Small and Medium Enterprises (SMEs) for the improvement of production management. Data: The data used in the paper are grounded on the scientific articles, reviews and empirical studies, related to the performance and performance indicators in production management. The set of most adequate performance indicators based on a relevant literature review and used in the model, represents performance indicators for the planning phase that are the most suitable for SMEs. Tools: The simulation model is developed in a spreadsheet environment. The use of spreadsheet applications enables simple data entry, processing, editing, analyzing and output reports compiling. Findings: Simulation results show the overall efficiency of the developed model in the determination of adequate performance indicators. They influence overall adequacy of performance indicators on the observed phase. Contribution: The main contribution of this paper lies in the model developed to maximize the adequacy of the performance indicators, suitable for use in the production management of SMEs.