CATWOE is a mnemonic device used in Soft Systems Methodology (SSM) to ensure that a Root Definition (a concise description of a human activity system) is rigorously formulated, well-structured, and comprehensive. It serves as a checklist to verify that all necessary components of a system definition are present, or conversely, as a guide to construct a Root Definition from scratch.
The mnemonic stands for the following six elements:
- C – Customers: These are the individuals or groups who are the victims or beneficiaries of the system’s activities. They are the people affected by the transformation process.
- A – Actors: These are the agents (people or groups) who carry out the activities involved in the transformation process. They are the ones who would “do” the work if the system were made real.
- T – Transformation: This is the core process of the system that converts a specific input into an output. Ideally, the input must be present in the output but in a changed state (e.g., “unpainted fence” to “painted fence”). It describes what the system does.
- W – Weltanschauung (Worldview): This German term refers to the specific view of the world or set of beliefs that makes the definition of the system meaningful. It explains why this particular transformation is being done and provides the context for the system’s purpose.
- O – Owner: This refers to the person, group, or agency with the power to modify, stop, or abolish the system. They are the decision-takers with ultimate authority over the system.
- E – Environmental Constraints: These are elements outside the system boundaries that the system must take as given. They are factors the system cannot control but which act as constraints or enablers (e.g., laws, budgets, ethical standards).
Sources: Checkland, P., & Poulter, J. (2007). Learning for action: A short definitive account of soft systems methodology, and its use for practitioners, teachers and students. Wiley Global Education UK.