For decades, organisations have grappled with the question of how many direct reports a manager can effectively oversee. This concept, known as “span of control”, has significant implications for organisational structure, efficiency, and performance. A comprehensive review of scientific literature conducted by the Centre for Evidence-Based Management (CEBMa) in 2021 sheds new light on this important topic, challenging long-held assumptions and providing nuanced insights for modern organisations.
Myth of the magic number
Perhaps the most striking finding from the CEBMa review is that there is no universal “magic number” for an optimal span of control. This conclusion flies in the face of traditional management thinking, which has often sought to prescribe ideal ratios of managers to subordinates.
For centuries, the “rule of 10” was considered the standard, dating back to early Egyptian times. However, empirical studies conducted since the 1950s have consistently shown that span of control is dependent on multiple factors, rendering a one-size-fits-all approach ineffective.
The research reveals substantial variations in average spans of control across different organisations and industries. For instance, Wallin et al (2014) found a mean span of control of 27 subordinates, with notable differences between human services (mean =30) and technical services (mean =16). Other studies reported spans ranging from as low as nine to as high as 77 direct reports. This wide variability underscores the need for a more careful approach to determining appropriate spans of control.
Impact of span of control
While there may not be a universally optimal number, the research does indicate that the span of control has significant implications for organisational performance.
Generally, larger spans of control were associated with negative performance outcomes. A study by Hoffer (2001) in airline companies found a strong negative correlation (r = -0.75) between the span of control and group performance. This suggests that as managers are tasked with overseeing more subordinates, their ability to manage and support their team effectively may diminish.
The influence of span of control extends beyond just group performance. It also plays a crucial role in moderating the impact of leadership styles on work-related outcomes. Doran et al (2004) found that a large span of control decreased the positive effects of transformational and transactional leadership styles, while amplifying the negative effects of management-by-exception and laissez-faire styles.
This finding highlights the complex interplay between the span of control and leadership effectiveness, suggesting that even highly skilled leaders may struggle to maintain their positive impact when overseeing too many direct reports.
Factors
The CEBMa review identifies several key factors that organisations should consider when determining appropriate spans of control:
Employee autonomy and expertise: Organisations with higher levels of employee autonomy and empowerment can generally support larger spans of control. When employees are capable of self-management and independent decision-making, managers can effectively oversee more subordinates.
Technological support: The use of advanced information and communication technologies can facilitate larger spans of control. Bloom et al (2014) found that technologies supporting employee decision-making and information sharing allow for wider spans of control.
Work complexity: The nature and complexity of the work being supervised play a crucial role. More complex tasks that require frequent managerial intervention may necessitate smaller spans of control.
Managerial capabilities: The skills, experience, and leadership style of individual managers influence their ability to manage larger teams effectively.
Organisational structure and Goals: The overall structure of the organisation and its strategic objectives should inform decisions about span of control.
Implications for managers
The findings from this research have several important implications for both managers and organisations:
Customised approach: Rather than adhering to fixed rules or ratios, organisations should adopt a flexible approach to the span of control that considers contextual factors specific to their industry, workforce and objectives.
Regular assessment: Given the dynamic nature of modern workplaces, organisations should regularly assess and adjust spans of control to ensure they remain appropriate as conditions change.
Leadership development: Organisations should invest in leadership development programmes that help managers effectively lead larger teams when necessary. This may include training in delegation, communication and the use of technology to support team management.
Technological infrastructure: Investing in technologies that support communication, coordination and decision-making can help organisations maintain larger spans of control without sacrificing effectiveness.
Employee empowerment: Fostering a culture of employee autonomy and empowerment can allow for larger spans of control while potentially improving overall organisational performance.
Challenges, considerations
While a larger span of control may seem appealing from an efficiency standpoint, the research highlights several potential pitfalls:
Manager burnout: Studies show that larger spans of control are associated with increased perceived job demands for managers (Brown et al, 2013) and predict higher manager turnover rates (Kraichy & Schmidt, 2019).
Relationship quality: Several studies found that a large span of control negatively affects the quality of leader-member relationships (Schriesheim et al, 2000; Schyns et al, 2005, 2012). Given the importance of these relationships for employee performance and satisfaction, this is a significant concern.
Ethical leadership: A study by Bormann et al (2018) found that span of control was positively related to ethical leadership variability, suggesting that managers with larger teams may struggle to maintain consistent ethical leadership behaviours.
Conclusion
The quest for a universally optimal span of control may be misguided, but this research provides valuable insights for organisations seeking to balance managerial effectiveness with organisational efficiency.
By considering the various factors that influence the span of control and regularly assessing their approach, companies can make more informed decisions about their organisational structure and managerial responsibilities.
As workplaces continue to evolve, particularly in the wake of technological advancements and changing work arrangements, the conversation around the span of control will likely continue. Future research may explore how emerging technologies, remote work and new organisational structures impact optimal spans of control.
For now, organisations would do well to heed the evidence and adopt a flexible, context-sensitive approach to this crucial aspect of organisational design.
Nguwi is an occupational psychologist, data scientist, speaker and managing consultant at Industrial Psychology Consultants (Pvt) Ltd, a management and HR consulting firm. — 0772 356 361 or [email protected]
