Flexibility is a term that is presumed to be meaningful across different levels of analysis in an organisation. It has been suggested that flexibility is required by organisations, groups, and individuals to deal with an increasingly complex and dynamic organisation and global environment. Authors have proposed that organisational flexibility enables a firm to achieve a better 'fit' with their environment and create a sustainable competitive advantage. The group level literature promotes flexibility at this level of analysis as important for group effectiveness and successful project completion. The individual flexibility literature suggests that people who are flexible are more likely to be satisfied and effective than individuals who are inflexible. Despite the importance placed on the construct of flexibility, it is a relatively under explored construct, both theoretically and empirically. This is due in part to the lack of definitional precision and inconsistency in the operationalisation of flexibility at each level of analysis. Consequently, little is known about the meaning of flexibility and the relationship of this construct with contextual and performance variables. This research addresses the limitations of the current literature on flexibility by developing a testable multi-level framework of flexibility. Flexibility is defined in this research as an organisation's, group's, and individual's ability to be proactive, adaptable, and resilient. Three primary research questions were addressed in this thesis. The first question addressed what are the characteristics of flexibility at the organisation, group, and individual level of analysis. The second overarching research question of interest in this thesis examines how flexibility at each level of analysis is related to performance. The third overarching research question examined what factors impact flexibility at each level of analysis. To address these three research questions at each level of analysis, a theoretical review and an empirical study were conducted. The first empirical study, focused on flexibility at the organisational level of analysis. This study involved the exploration of seven specific research questions that were developed from the theoretical review. This study used cross-sectional secondary data of private sector Australian organisations. Flexibility was defined as proactivity, adaptability, and resilience. This research examined the relationships between each of the flexibility components and improvements in several organisational level outcomes. Also, the impact of the contextual variables level of organisational control, degree of structure, and competition changes on the flexibility-performance relationship was investigated. Analysis techniques included moderated regression analysis. Results showed support for the positive association between flexibility and performance. Flexibility interacted with competition and structure to influence performance, but control was found to have no moderating effect on the flexibility-performance relationship. The second empirical study investigated group flexibility. This study took a sequential, mixed method research approach, using qualitative data to explore group flexibility and quantitative analysis to explore the broad relationships found among variables from the qualitative research. Using this approach, this study addressed five specific research questions that were developed from a theoretical review, including defining group flexibility, the nature of group flexibility conceptualisation, the relationship between flexibility and group performance, factors that may enhance group flexibility, and factors that may reduce group flexibility. Findings showed group flexibility was described consistently between participants and the existing literature, proposing group flexibility is a group's ability to search and consider alternatives, be adaptable, and resilient. Results also suggested a positive relationship between group flexibility and several outcomes, including stakeholder satisfaction, personal development and satisfaction, group morale, and group confidence. The final study examined individual level flexibility. Based on the theoretical exploration of individual flexibility, in this study, individual flexibility was defined as the ability to be proactive, adaptable, and resilient. This empirical research focused specifically on managerial level flexibility. Due to the similarities in descriptions of individual flexibility and managerial flexibility in the literature, the definition of individual flexibility was applied to the managerial level. The study investigated changes in flexibility levels over time using executive coaching as the literature promotes executive coaching as an individual flexibility developmental tool. This study examined eleven leaders undertaking executive coaching with individual flexibility being measured at three points in time, pre coaching, the middle of coaching, and post coaching. Findings were consistent with the proposition of the positive impact of executive coaching on flexibility as the data showed leaders' individual flexibility levels increased from pre coaching to post coaching, with a significant linear trend over time. The results of these three studies are integrated to inform the multi-level framework of flexibility which was developed in this thesis. This framework provides a systematic, comprehensive, and tangible definition of flexibility at each level of analysis, providing a rich description of the characteristics of each flexibility component. This research advances our understanding of flexibility, which I hope will encourage further research on the construct. For managers and practitioners, this research provides a clear description of flexibility at each level of analysis and offers indicators of flexibility at each level to encourage the measurement and development of organisational, group, and individual flexibility. Also, this research provides empirical evidence of the benefits of flexibility, helping to provide legitimacy for the inclusion of flexibility into the organisation, in areas including strategic planning, organisational design, group design, recruitment and selection, and training and development. Furthermore, this multi-level model allows practitioners to be more focused in developmental efforts for organisation, group, and individual flexibility. This research provides several interesting areas for future research.