The design and empirical validation of a generally applicable model of value-creating business processes constitutes the core focus of this dissertation. Business processes are conceptualized as generators of Process Value Added (PVA) in manufacturing and service settings, with direct links to corporate performance, efficiency, and profitability. This principle was implemented in the present research within the context of the mechanical engineering manufacturing industry. The theoretical foundation of the dissertation rests on the assumption that a firm’s level of PVA is determined by the configuration and management of value-creating flows across both primary and support processes within the given production system. This represents a novel performance-management perspective that has not yet been articulated in the domestic literature. In Czech business practice, the prevailing approach to added-value assessment remains operationalized, managerial decision-making is therefore based primarily on technical, technological, and performance parameters of the respective operation or of the production process as a whole. The pre-pilot (secondary) research combines original inquiry with a bibliometric analysis (Web of Science, VOSviewer). It focuses on the topics “performance added value” and “process value added ” with the aim of generating relevant and objective outputs to inform the structure of variable parameters and the corresponding relationships within the proposed general PVA model. The primary research, integrating both quantitative and qualitative methods, tests relationships between process determinants (e.g., management level, process characteristics, innovation, digitalization, and automation) and PVA. The quantitative component employs statistical techniques including normality testing, one-way ANOVA, cluster analysis (K-means), and dimensionality reduction (PCA). The qualitative component uses case studies covering the principal size categories of mechanical engineering firms (the Department of Management’s model companies at VŠTE, ÚPS). The dissertation presents the proposed methodological procedure for evaluating PVA at the level of processes and operations and demonstrates its practical computation in the model companies, including the corresponding evaluation. The integrative outcome of the dissertation is a verified general model of value-creating processes for size categories of mechanical engineering enterprises, positioned as a new instrument for strategic management of business entities.