Complex socio-technical systems: Characterization and management guidelines.

Although ergonomics has paid increasing attention to the perspective of complexity, methods for its operationalization are scarce. This study introduces a framework for the operationalization of the "attribute view" of complexity, which involves: (i) the delimitation of the socio-technical system (STS); (ii) the description of four complexity attributes, namely a large number of elements in dynamic interactions, a wide diversity of elements, unexpected variability, and resilience; (iii) the assessment of six management guidelines, namely design slack, give visibility to processes and outcomes, anticipate and monitor the impacts of small changes, monitor the gap between prescription and practice, encourage diversity of perspectives when making decisions, and create an environment that supports resilience; and (iv) the identification of leverage points for improving the STS design, based on both the analysis of relationships among the attributes and their classification as irreducible/manageable complexity, and liability/asset. The use of the framework is illustrated by the study of an emergency department of a University hospital. Data collection involved analysis of documents, observations of work at the front-line, interviews with employees, and the application of questionnaires.