Recognising whether a challenge is complicated or complex helps teams choose strategies, tools, and approaches that fit the situation. Complicated problems, such as building an aircraft or coordinating logistics, follow predictable steps and lend themselves to standard project management and optimisation techniques. Complex challenges, such as climate adaptation or community-led change, emerge from interacting elements, uncertainty, and feedback, and require more adaptive and participatory ways of working.
In practice, most real-world initiatives contain both complicated and complex elements. The challenge lies in recognising which aspects can be planned or engineered, and which must be explored, tested, and adapted over time. Approaches grounded in systems thinking and complexity-aware practice help teams navigate this balance, combining structure with learning and responsiveness.
In many fields, this distinction has become increasingly important in planning, evaluation, and organisational learning. A range of frameworks now help teams diagnose the nature of their challenges and match their methods to dynamic conditions. For a structured introduction to systems thinking concepts and tools, you can also visit the systems thinking resources page.The resources below explore how recognising complexity can support adaptive management, continuous learning, and collaborative decision-making.
A good starting point is the post Complicated or complex? Knowing the difference matters, which outlines how to recognise different types of challenges and choose approaches that fit. It’s a practical entry point for those working in policy, sustainability, and collaborative initiatives.
Distinguishing complicated from complex
The resources below help practitioners recognise the difference between complicated and complex situations, and explain why the distinction matters for planning, evaluation, and response.
Complicated and Complex Systems: What Would Successful Reform of Medicare Look Like?
This 2002 paper by Sholom Glouberman and Brenda Zimmerman explains how healthcare reforms often fail by treating complex systems as complicated ones. It remains one of the most widely used and accessible introductions to the distinction between simple, complicated, and complex problems, and has been taken up well beyond its original health context.
Tackling wicked problems: A public policy perspective
This 2007 Australian Public Service Commission paper defines ‘wicked problems’ and outlines key skills for policymakers working in complex environments. It remains a useful primer for understanding the limits of traditional policy tools.
Understanding and working with complexity
The following resources offer complementary perspectives on working with complexity in practice, from sense-making and decision-making through to relational and process-oriented approaches.
Taking responsibility for complexity
This ODI paper by Harry Jones helps decision-makers recognise when and why policy problems are complex. It warns against applying linear solutions and offers practical guidance for achieving results in dynamic contexts. A related ODI working paper expands on these themes and offers further insights into policy implementation in the face of complexity.
Systems approaches to public sector challenges
This 2017 OECD report explores how systems approaches can help address complex policy issues. It highlights adaptive strategies, cross-sector collaboration, and inclusive design, supported by international case studies.
No systems transformation without systems literacy
This 2026 open-access paper by Hanna Ewell and colleagues examines how CGIAR has engaged with systems thinking across five decades of agricultural research for development. It argues that systems transformation requires not just tools but the institutional capacity to select and apply different systems approaches appropriately in complex settings.
Managing complexity (and chaos) in times of crisis
This 2021 field guide by Dave Snowden and Alessandro Rancati, published by the European Commission’s Joint Research Centre, applies the Cynefin framework to decision-making in crisis and complexity. It introduces a four-stage process (assess, adapt, exapt and transcend), alongside tools for sensing, constraint management, and narrative-based assessment.
Process complexity
A 2021 paper by Jean Boulton that reframes complexity as an ongoing process of “becoming,” where patterns of relationships emerge, stabilise, and dissolve over time. It introduces the idea of ontological uncertainty and highlights implications for adaptive, context-aware practice. A related 2024 blog post, Insights into the science of complexity, provides an accessible introduction to these ideas.
Theory U: addressing the blind spot of our time
An executive summary by Otto Scharmer (2007) outlining Theory U as a framework for working with complexity through shifts in attention and awareness. It emphasises relational sensing and has been widely used in organisational learning and systems change work.
Complexity-aware evaluation, learning and adaptation
Embedding learning in systems change
This practical framework by Kecia Bertermann and Julia Coffman (2026)supports learning and evaluation practitioners working with systems change strategies. It focuses on five connected elements: hypotheses, assumptions, learning questions, confirming and disconfirming evidence, and routine sense-making and reflection. Useful for teams wanting to move beyond static metrics and linear outcomes toward learning that supports adaptation.
Supplementary guide: handling complexity in policy evaluation
This 2025 UK HM Treasury guide outlines practical frameworks for evaluating policies in complex contexts. It explains why complexity matters for policy and evaluation, and introduces adaptive tools and real-time learning strategies for unpredictable environments.
How to carry out a complex evaluation
This 2021 CECAN guide provides frameworks, toolkits, and case studies for designing and managing evaluations in complex settings. It offers advice for addressing uncertainty, interdependencies, and emergence in ways that are both credible and adaptive.
Introducing systems- and complexity-informed evaluation
This 2021 chapter by Eleanor Gates, Meg Walton, Patricia Vidueira, and Marc McNall introduces systems- and complexity-informed evaluation as a distinct field of practice, drawing on examples from diverse programme contexts. It appears in the edited volume Systems and Complexity-Informed Evaluation: Insights from Practice, New Directions for Evaluation.
Complexity-aware monitoring and evaluation
This 2021 paper by Thomas Hertz, Erik Brattander, and Lottie Rose in the Journal of MultiDisciplinary Evaluation introduces complexity-aware monitoring and evaluation as a practical approach for programmes working in dynamic, multi-actor settings.
Complexity-aware evaluation for learning: A case study of a developmental approach
This 2025 paper by Estelle Rosenberg, Karen Kotschy, and Stuart Pollard in the Journal of MultiDisciplinary Evaluation offers a detailed case study of complexity-aware evaluation in practice, illustrating how a developmental approach supports learning and adaptation over time.
Quick answers to common questions
What is complexity-aware practice?
Complexity-aware practice recognises that outcomes in complex settings are often uncertain and cannot be fully planned in advance. It focuses on learning, adaptation, and shared sense-making, helping people respond to change as it unfolds.
When is a complexity-aware approach useful?
It is most useful when cause and effect are unclear, multiple actors are involved, and outcomes emerge over time. In these situations, fixed plans are often less effective than approaches that support experimentation, reflection, and adjustment.
How is this applied in practice?
In practice, this often involves combining light structure with ongoing learning. People may use simple frameworks, facilitation, and evaluation approaches to guide action, while staying open to what is emerging and adjusting as they go.
For related approaches, see the Systems thinking and complexity-aware approaches in practice hub page. Related topics include adaptive management, Theory of Change, and reflective and reflexive practice.
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[* Image: Adobe / Piotr Krzeslak]