What is systems thinking?

Definition

Projects, programmes and portfolios are made up of multiple, interacting systems containing connected elements that form patterns, relationships and rules.

Systems thinking contrasts with linear thinking (see Figure 1.3.5), which is suitable for systems where cause and effect are predictable. A complex system is more than the sum of its parts; systems thinking focuses on the interconnections between elements. It recognises that we cannot predict a whole system’s behaviour, but we can analyse its elements and focus on patterns of change.

Definition from APM Body of Knowledge 8th edition

Why is it important?

Complex projects need both technical and managerial leaders who understand each other’s needs and requirements, and who consequently can work in an integrated way. 

There is substantial evidence that an integrated project management and systems engineering approach adds value by reducing the need for re-planning and rework, and optimising the risk margin, allowing projects to fulfil their objectives both on time, and to budget.

Figure 1.3.5  The natures of linear and systems thinking
Source: APM Body of Knowledge 8th edition

How projects could benefit from systems thinking?

Traditional project management often uses linear tools like Gantt charts, which overlook the complex interactions between tasks.

As projects become more intricate, systems thinking offers valuable benefits:

• More realistic planning: It accounts for unexpected tasks (like rework), improving cost and schedule estimates.
• Better product integrity: It helps anticipate challenges at interfaces and identify enabling tasks, reducing surprises.
• Deeper stakeholder understanding: It encourages a broader view of stakeholder needs across the full project lifecycle.

Systems thinking complements—rather than replaces—traditional methods, offering a holistic approach better suited to modern project complexity.

Strategic and systemic approaches 

A holistic approach ensures change initiatives remain aligned to long-term organisational goals. This enhances overall system performance and value delivery. Understanding the complex interplay of the different elements in an organisation is also essential in understanding organisational change and business transformation. Its application to change management can:

• reveal conflicts between stakeholders and sources of resistance to change
• identify and anticipate potential impacts and consequences
• determine communication strategies
• guide and adapt to culture shifts

Systems thinking helps transformation leaders appreciate broader dynamics and highlight interdependencies, feedback loops and leverage points. With this knowledge, project professionals can spot unintended consequences of actions, and respond proactively to enhance overall system performance and value delivery.

Doing the Right Project

As projects grow in complexity, systems thinking becomes essential. This guide introduces systems thinking, explains its value in selecting and validating projects, and shows how to avoid investing in those projects unlikely to deliver expected benefits.

Written by the APM Systems Thinking Interest Network, for those identifying, defining, sponsoring or commissioning projects as well as project professionals involved at the formative stages of a project.

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Systems thinking: the what, why and when

When applied before the start of a project, systems thinking can help ensure that funding is approved for projects that are organisationally valuable and financially viable. This is especially important when addressing ‘complex’ problems, where the problem and/or solution are unclear, where the solution cannot be disentangled from the problem or where the project environment changes over time.

Applying systems thinking becomes essential during the following stages:

1. Shaping the early life cycle. Applying systems thinking in the creation and definition of business change strategies can result in improved business case clarity, accuracy and completeness. Additionally, more comprehensive identification and assessment of risks can be achieved, as well as greater stakeholder buy‑in.
2. Defining outputs. Applying systems thinking can lead to a better understanding of business requirements, more clearly defined objectives, reduced unintended consequences, and improved risk, change and benefits management.
3. Establishing governance and oversight. Applying systems thinking can result in a more appropriate governance structure, quicker team mobilisation and increased commitment to project success.

Finally, systems thinking supports the continuous balance of the portfolio by regularly evaluating the projects’ relevance to the organisation. Project performance and benefits realisation can be assessed in a richer context, taking into account the latest information from the external and internal environment offered by systems thinking techniques.

This article is an edited extract which appeared in the summer 2025 edition of Project journal.

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APM Body of Knowledge 8^th edition

The APM Body of Knowledge is a foundational resource providing the concepts, functions and activities that make up professional project management. It reflects the developing profession, recognising project-based working at all levels, and across all sectors for influencers, decision makers, project professionals and their teams. 

Systems thinking: how is it used in project management

All project professionals that have an interest in or want to know more about systems thinking. The study aims to produce a guide on how to apply systems thinking in projects and to understand whether systems thinking is a critical success factor in complex projects. 

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Systems thinking: A must have project management competency to help you do the right project not just do the project right

Always striving to improve, I decided to use my break to refresh my project management qualifications, but I also wanted to focus on strengthening my strategic thinking and problem-solving abilities, so I’d be better equipped to “do the right project” in the future

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Systems thinking in project management: A case study in success for the NHS

What systems thinking can offer portfolio, programme and project managers

APM Systems Thinking Interest Network

Our purpose? To promote systems thinking as a methodology to improve delivery of complex change initiatives. 

We also aim to foster and encourage better integration between project management and systems engineering, drawing on industrial and academic expertise from across the two professional bodies.