Decline of socio-technical systems is of growing interest for sustainability transitions. It contributes to reducing negative impacts from problematic technologies and facilitates a quicker diffusion of more sustainable alternatives. However, key approaches for studying transitions, such as the technological innovation systems (TIS) framework, are often better equipped to investigate the initial phases of innovation systems than analyzing their decline. Inspired by the functional analysis of TIS dynamics, this paper investigates if similar key processes are at work when a TIS is in decline. We review existing literature and derive a preliminary set of processes: de-legitimation, repulsion of direction of search, market decline, and resource demobilization. To illustrate the usefulness of this approach, we apply it for studying the decline of four TIS in the energy sector: nuclear power, incandescent light bulbs, oil-based heating and internal combustion engine cars. Data on these cases was collected and analyzed through a directed literature review. Our findings suggest that a defined set of decline processes will facilitate systematic analyses of TIS decline across technologies and places, and could be used by policymakers to identify ways to accelerate and guide decline.

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