Theories of management provide different ways of understanding how organisations can be led effectively. Two important perspectives are thesystems approachand thecontingency approach. Both move beyond early “one best way” classical theories and instead highlight the complexity and adaptability required in modern organisations.

Thesystems approachviews the organisation as an integrated whole made up of interdependent subsystems such as HR, finance, operations and procurement. It is based on systems theory, seeing organisations as “open systems” that interact with their external environment. Inputs such as people, information and resources are transformed into outputs such as products, services and stakeholder value. Feedback loops are essential to monitor performance and make adjustments. The key idea is synergy — the whole is greater than the sum of the parts. For example, in procurement, sourcing decisions influence not only supplier performance but also finance (budgets), operations (continuity), and CSR (sustainability). A systems approach ensures that procurement strategies are aligned to wider organisational goals and continuous improvement.

Thecontingency approachdevelops this idea further, arguing that there is no universal way to manage. Instead, the best approach depends on situational factors such as environment, size, technology, or workforce capability. It rejects “one-size-fits-all” rules and stresses that management must adapt. For example, in a stable market, a hierarchical structure with formal rules may work well, whereas in volatile markets, flexible and decentralised decision-making is more effective. In procurement, this could mean using strict process controls for routine, low-value items, but adopting agile, collaborative approaches when managing strategic supplier partnerships in uncertain global supply chains.

In comparison, the systems approach gives managers aholistic viewof how different parts of the organisation connect and interact with the external environment, while the contingency approach emphasisesadaptabilityand situational leadership. Together, they suggest that effective managers need both a broad systems perspective and the ability to tailor their approach depending on context.

In conclusion, the systems approach stresses coordination, integration and feedback across the organisation, while the contingency approach stresses flexibility and the idea that “it depends.” Both are highly relevant to procurement and supply leaders who must integrate across functions and adapt strategies to dynamic and uncertain supply environments.