Integrating Saks (2006) and Schaufeli et al. (2006): towards a conceptual framework and typology of sustainable employee engagement

Purpose This study integrates two foundational perspectives on employee engagement: job demands–resources (JD-R) and social exchange theory (SET), through the lens of psychological capital (PsyCap: hope, efficacy, resilience, optimism). Additionally, it incorporates conservation of resources (COR) theory to reinforce the resource gain/loss logic underpinning sustainable engagement. The purpose of this study is to develop a conceptual framework and typology of sustainable employee engagement (SEE) that positions well-being and sustainability as central outcomes, directly aligned with the United Nations Sustainable Development Goals (SDGs). Design/methodology/approach Using an integrative literature review, the paper consolidates structural, relational and psychological resource perspectives. JD-R highlights the balance between demands and resources, SET emphasises reciprocity and perceived support, while PsyCap offers the psychological resources required to sustain engagement. COR theory further frames engagement as the process of protecting and accumulating valued resources. These dimensions are synthesised into a multidimensional SEE framework and typology. Findings Enduring engagement requires more than favourable job design or supportive exchanges. PsyCap functions as a pivotal mechanism that transforms organisational resources and social reciprocity into long-term, resilient engagement. Moderators such as psychological detachment and goal clarity act as boundary conditions to prevent over-engagement and burnout. The typology identifies unfocused, sustainable, stuck and over-engagement states. Research limitations/implications This conceptual model requires empirical testing across diverse organisational contexts. Social implications The framework supports workplaces that foster employee well-being and contribute to SDG 3 and SDG 8. Originality/value By uniting JD-R, SET, COR theory and PsyCap, this study advances engagement theory into a sustainability-oriented paradigm. It provides actionable strategies for building resilient, high-performing employees.