Assessing technology maturity in open source hardware ecosystems presents specific challenges connected to the openness of the technologies involved. Traditional Technology Readiness Levels (TRLs) and other complementary frameworks cannot fully address the readiness assessment of open source technologies, as they rely on intellectual property-based mechanisms, assume well-defined contexts for implementation, and lack a comprehensive evaluation of the adoption challenges in open source systems. This article presents the Open Source Technology Readiness Levels (OSTRLs), a new readiness assessment framework for evaluating the openness maturity of technologies to be integrated into open source ecosystems, considering critical aspects such as intellectual property freedom and accessible documentation. Based on TRLs and open design principles, the OSTRLs classify the openness readiness of technology across nine levels, from potential to full openness, considering product and process openness, i.e., transparency, replicability, reusability, and accessibility. The use of OSTRLs is contextualized with other complementary assessment tools to show their potential use as part of a comprehensive evaluation of the aspects connected to the implementation of open source technology. The use of the OSTRLs is then validated by assessing open source technologies in the distributed recycling for additive manufacturing (DRAM) ecosystem, a model that combines localized plastic recycling and 3D printing. The OSTRLs provide a structured way to assess open source technology ecosystems, such as DRAM, identifying not only mature solutions or areas for improvement in openness, but also existing trends, opportunities, risks, and gaps in adoption. This framework can support researchers, practitioners, institutions, and policymakers in strategic decision-making and guide future research toward sustainable and circular innovation systems. • Open Source Technology Readiness Levels assess openness maturity of technologies. • OSTRLs include nine assessment levels of product and process openness maturity. • Other readiness frameworks can be used with OSTRLs for broader adoption assessment. • OSTRLs can assess existing real-world ecosystems adopting open source technology. • OSTRLs support strategic decision-making and future research in sustainable systems.
Romani et al. (2026) studied this question.