Purpose– This paper aims to go a step further in the analysis of double fit in the human resource management (HRM) strategy context, exploring how its effect on performance is influenced by employees’ perceptions about the HRM strategy. Traditionally, the literature has considered the need for a double fit (horizontal and vertical) in the design of HRM strategies. However, as recent critical reviews have argued, a deeper theoretical analysis seems to be needed to understand fully how they affect organisational performance, and why firms with similar levels of alignment have different human resource outcomes.Design/methodology/approach– Based on the literature review, the paper proposes a new theoretical model combining two fields of the strategic HRM literature which had been traditionally disconnected: the double fit approach and the literature on employee satisfaction and involvement. The design of the HRM strategy is reviewed considering the classical distinction between universalistic, contingent, contextual and configurational perspectives.Findings– The findings of this paper provide an alternative model to examine the double fit in the HRM strategy context.Originality/value– Drawing on these approaches, the paper proposes the introduction of the “system strength” construct, which measures the perceived robustness of the HRM system, as a moderator of the effects of double fit on organisational performance.