SECI model

How does an individual's private insight become an organisation's shared knowledge, and then someone else's skill? The SECI model traces that spiral.

The SECI model, developed by Ikujiro Nonaka and Hirotaka Takeuchi, describes how knowledge is created in organisations through continuous conversion between tacit and explicit forms. Its name comes from its four modes: socialisation, externalisation, combination, and internalisation, through which knowledge spirals and grows.

The four conversions

Each mode converts knowledge from one form to another. Socialisation shares tacit knowledge directly between people through shared experience, observation, and practice, as an apprentice learns from a master. Externalisation articulates tacit knowledge into explicit form, putting intuition and know-how into words, models, or concepts. Combination assembles explicit knowledge from different sources into new explicit knowledge, as scattered data is synthesised into a report. Internalisation absorbs explicit knowledge back into tacit skill, as written procedures become, through practice, fluent competence.

The spiral

The model's central image is a spiral rather than a cycle. Knowledge does not merely circulate through the four modes; it grows as it does, moving from individual to group to organisation and back, amplifying and enriching at each turn. A personal insight, made explicit, combined with others, and absorbed by many as new skill, ends up as organisational knowledge far larger than where it began. Knowledge creation, in this view, is an ongoing, expanding process of conversion, not a one-off act.

Why it matters

The SECI model's contribution was to take knowledge creation seriously as something organisations do, and to show that it depends on the interplay between tacit and explicit knowledge rather than on either alone. It highlights the often-neglected conversions, especially externalisation, making the tacit explicit, and socialisation, sharing the tacit directly, that document-focused knowledge management ignores. It also implies that firms must create the conditions, shared spaces, time, trust, in which these conversions can happen.

The SECI model gave organisations a vocabulary for the otherwise invisible process by which knowledge is created and grows. Whether or not its four modes capture reality perfectly, its core insight endures: that an organisation's knowledge expands through the constant, deliberate conversion between what can be said and what can only be shown.