The objective of this study was to analyse the evolutionary field of sustainable human resource management (S-(HRM)) over four strategically chosen sub-periods in order to understand its behaviour in the period from 1991 to 2024. We started by conducting a comprehensive review of research articles related to our topic, aiming to produce a scientific, accurate, and well-argued result through quantitative and empirical research, incorporating both factorial and exploratory analyses. We began by carrying out an exhaustive review of different research articles related to our topic in order to generate a scientific, truthful and argumentative result, from quantitative and empirical research, in relation to a factorial and exploratory analysis. Regarding the analysis of the period between the years chosen for this research (1991–2024), we observe that the subject analysed has gradually evolved, with an increase in publications, as evidenced in the different graphs. In turn, the analysis of the most prominent themes for the sub-periods is illustrated by their classification in strategic diagrams and structured spheres quantified in the statistical software SciMAT v1.1.06, through keywords, which is the strategy best adapted to this type of research. The analysis (keywords) configures the most important concepts of the research field.

(1) Background: The survival and growth of startups in their early stages is negatively impacted by the lack of financial sustainability and scarce resources that entrepreneurs face during the first 5 years. This is known as the Valley of Death. This study seeks to identify key factors that influence the financial sustainability of start-ups during the Valley of Death, which demands a significant amount of funding and government support. (2) Methods: A quantitative methodology was employed, based on a worldwide literature review that pointed out the variables of the object of study; the information collection process was conducted through a questionnaire applied to 352 entrepreneurs in an innovative ecosystem. This study empirically applies a structural equation model to determine the relationship between constructs. (3) Results: A comprehensive analysis of results indicates that indicators such as positive sales performance, sufficient financial solvency to meet short- and long-term commitments, accurate pricing policies, and access to government and banking support are the primary factors affecting the sustainability of start-ups in the early stages. (4) Originality: This study provides original and relevant insights into the indicators that affect the financial sustainability of start-ups during the Valley of Death and offers interesting insights for governments, institutions, and entrepreneurs to foster innovative ecosystems; it also contributes to the extant literature on early-stage entrepreneurial failures.