Purpose: The purpose of this paper is to study the role of slack (both moderating and mediating) to stimulate the relationship between total quality management (TQM) factors and innovation outcomes relative to gaining competitive industry advantages. Design/methodology/approach: The research methodology includes a multi-item scale questionnaire completed in three waves between 2016 and 2017, and later analysed in 2018. A final response rate of 29.5 per cent was obtained, representing 190 organisations from both manufacturing and service industries in the United Arab Emirates (UAE). Partial least squares structural equation modelling was used to test the multi-collinearity, moderation and mediation analysis. Findings: Analysis confirmed that factors such as continuous improvement (CI), human resource management (HRM) and information measurement (IM) were positively linked to innovation. However, when slack was introduced as a moderator, innovation outcomes were stimulated through HRM and IM. The results indicate that slack acts as a full mediator for management leadership but only partially mediates supplier quality, IM, CI, HRM and process management. Research limitations/implications: In terms of geographical coverage, research was limited to the UAE. Organisations striving for excellence through innovation may benefit from the outcomes, as they help in understanding the relationship between TQM and innovation moderated and/or mediated by slack. This could also lead businesses to develop new strategies that harmonise TQM policies with "rationale" slack policies, thus, promoting innovation. Originality/value: This study is the first to examine the use of slack to stimulate the relationship between TQM factors and innovation outcomes. Using slack as a mediator can help in understanding when TQM might influence innovation, while slack as a moderator could invert the relationship between the two.